Awesome JVM !Awesome (https://cdn.rawgit.com/sindresorhus/awesome/d7305f38d29fed78fa85652e3a63e154dd8e8829/media/badge.svg) (https://github.com/sindresorhus/awesome)

A curated list of awesome JVM low level, performance and non-framework related stuff.

- Awesome JVM (#awesome-jvm)
- **Bytecode** (#bytecode)                            
- **Garbage collectors** (#garbage-collectors)        
- **Load tools** (#load-tools)                        
- **Languages** (#languages)                          
- **Machine Learning** (#machine-learning)            
- **Memory and Concurrency** (#memory-and-concurrency)
- **Metaprogramming** (#metaprogramming)              
- **Native** (#native)                                
- **Network** (#network)                              
- **Nix tools** (#nix-tools)                          
- **Profilers** (#profilers)                          
- **Runtimes** (#runtimes)                            
- **Virtual Machines** (#virtual-machines)            
- Resources (#resources)
- **Communities** (#communities)    
- **Documentation** (#documentation)
- **Media** (#media)                
- **People** (#people)              
- Contributing (#contributing)


Bytecode

Tools for bytecode manipulation and analysis.

⟡ asmtools (https://wiki.openjdk.java.net/display/CodeTools/asmtools) - Used to develop tools for the production of Java .class files.
⟡ Byte Buddy (http://bytebuddy.net) - Code generation library creating Java classes at runtime without the help of a compiler.
⟡ Jitescript (https://github.com/qmx/jitescript) - Bytecode generation library similar to BiteScript. 

Garbage collectors

Garbage collectors for the JVM.

⟡ Azul Pauseless Garbage Collection (https://www.azul.com/files/wp_pgc_zing_v52.pdf) - Providing continuous, pauseless operation for Java applications.
⟡ Balanced GC (http://www.ibm.com/developerworks/websphere/techjournal/1108_sciampacone/1108_sciampacone.html) - GC policy available in the Java Virtual Machine for IBM WebSphere Application Server V8.
⟡ Epsilon GC (http://openjdk.java.net/jeps/318) - Completely passive GC implementation with bounded allocation limit, and lowest runtime performance overhead possible.
⟡ G1 (http://www.oracle.com/technetwork/java/javase/tech/g1-intro-jsp-135488.html) - The Garbage-First Garbage Collector.
⟡ Shenandoah (http://openjdk.java.net/jeps/189) - Ultra-Low-Pause-Time Garbage Collector.
⟡ The Garbage Collection Handbook (http://gchandbook.org) - Book that addresses new challenges to garbage collection made by recent advances in hardware and software.
⟡ ZGC (http://mail.openjdk.java.net/pipermail/announce/2017-October/000237.html) - Garbage collector optimized for low latency and very large heaps.

Load tools

Tools that generate load and measure the system accurately without coordinated omission

⟡ Gatling (http://gatling.io) - Asynchronous non-blocking scenario driven load testing tool for testing HTTP servers.
⟡ wrk2 (https://github.com/giltene/wrk2) - A constant throughput, correct latency recording variant of wrk.

Languages

Languages running on the JVM.
⟡ Ceylon (http://ceylon-lang.org/) - Object-oriented, strong and static programming language with an emphasis on immutability, created by Red Hat.
⟡ Clojure (http://clojure.org/) - Dialect of Lisp created by Rich Hickey. Dynamically typed with emphasis on functional programming.
⟡ Erjang (http://www.erjang.org) - A JVM-based Erlang VM.
⟡ Eta (http://eta-lang.org/) - Pure, lazy, strongly typed functional programming language on the JVM.
⟡ Frege (https://github.com/Frege/frege) - Pure functional programming language in the spirit of Haskell.
⟡ gojava (https://github.com/sridharv/gojava) - Java bindings for Go packages.
⟡ Golo (http://golo-lang.org/) - A simple dynamic language that makes extensive usage of invokedynamic.
⟡ Groovy (http://www.groovy-lang.org/) - Optionally typed and dynamic language, with static-typing and static compilation capabilities.
⟡ Java (http://www.oracle.com/technetwork/java/javase/overview/index.html) - General-purpose, concurrent, strongly typed, class-based object-oriented language.
⟡ JRuby (http://jruby.org) - Implementation of the Ruby language on the JVM.
⟡ JPHP (https://github.com/jphp-group/jphp) - PHP on the Java VM.
⟡ Jython (http://www.jython.org) - Python for the Java Platform.
⟡ Kawa (http://www.gnu.org/software/kawa/) - Extension of the Scheme language, which is in the Lisp family of programming languages.
⟡ Kotlin (http://kotlinlang.org/) - Statically typed programming language for the JVM, Android and the browser.
⟡ LuaJ (http://www.luaj.org/luaj/3.0/README.html) - Java-centric implementation of lua vm built to leverage standard Java features.
⟡ Nashorn (http://openjdk.java.net/projects/nashorn/) - Lightweight high-performance JavaScript runtime in Java with a native JVM.
⟡ OCaml-Java (http://www.ocamljava.org/) - Supports OCaml language v4. Generates plain Java bytecode and have seamless integration with Java.
⟡ Rembulan (https://github.com/mjanicek/rembulan) - Rembulan is an implementation of Lua 5.3 for the JVM, written in pure Java with minimal dependencies.
⟡ Renjin (http://www.renjin.org/) - JVM-based interpreter for the R language for the statistical analysis
⟡ Scala (http://www.scala-lang.org/) - Strong and static programming language that combine object-oriented and functional programming ideas.
⟡ Xtend (http://www.eclipse.org/xtend/) - Flexible and expressive dialect of Java, which compiles into Java 5 source code.

Machine Learning
⟡ Deeplearning4j (https://deeplearning4j.org/) - Open-Source, Distributed, Deep Learning Library for the JVM.
⟡ H2O (https://www.h2o.ai/) - Fast statistical, machine learning & math runtime.
⟡ Smile (https://github.com/haifengl/smile) - Statistical Machine Intelligence & Learning Engine.

Memory and concurrency

Tools and data structures for efficient memory layout and concurrent access.

⟡ Agera (https://github.com/google/agera) - Reactive Programming for Android by Google.
⟡ Agrona (https://github.com/real-logic/Agrona) - Library of data structures and utility methods that are a common need when building high-performance applications.
⟡ Apache Arrow (http://arrow.apache.org/) - A high-performance cross-system data layer for columnar in-memory analytics.
⟡ bloofi (https://github.com/lemire/bloofi) - Java implementation of multidimensional Bloom filters
⟡ Cap’n Proto (https://capnproto.org/) - Insanely fast data interchange format and capability-based RPC system.
⟡ caffeine (https://github.com/ben-manes/caffeine) - A high performance caching library for Java 8.
⟡ Chronicle-Bytes (https://github.com/OpenHFT/Chronicle-Bytes) - Low level memory access wrappers.
⟡ Chronicle-Queue (https://github.com/OpenHFT/Chronicle-Queue) - Micro second messaging that stores everything to disk.
⟡ Chronicle-Map (https://github.com/OpenHFT/Chronicle-Map) - In-memory key-value store designed for low-latency and/or multi-process applications.
⟡ clj-ds (https://github.com/krukow/clj-ds) - Clojure's data structures modified for use outside of Clojure.
⟡ colfer (https://github.com/pascaldekloe/colfer) - Binary serialization format and class generator.
⟡ commons-math (http://commons.apache.org/proper/commons-math) - Library of lightweight, self-contained mathematics and statistics components.
⟡ CuckooFilter4J (https://github.com/MGunlogson/CuckooFilter4J) - Bloom filter replacement for approximated set-membership queries.
⟡ cyclops (https://github.com/aol/cyclops) - Integration modules for RxJava, Reactor, FunctionalJava, Guava & Javaslang.
⟡ Eclipse Collections (https://github.com/eclipse/eclipse-collections) - Collections framework for Java.
⟡ externalsortinginjava (https://github.com/lemire/externalsortinginjava) - Sort very large files using multiple cores and an external-memory algorithm.
⟡ failsafe (https://github.com/jhalterman/failsafe) - A lightweight, zero-dependency library for handling failures.
⟡ fasttuple (https://github.com/boundary/fasttuple) - Collections that are laid out adjacently in both on- and off-heap memory.
⟡ fast-uuid (https://github.com/jchambers/fast-uuid) - Java library for quickly and efficiently parsing and writing UUIDs.
⟡ FlatBuffers (http://google.github.io/flatbuffers/) - Efficient cross platform serialization library for C++, C#, Go, Java, JavaScript, PHP, and Python.
⟡ geohash (https://github.com/davidmoten/geo) - Java utility methods for geohashing.
⟡ gs-collections (https://github.com/goldmansachs/gs-collections) - Goldman Sachs collections framework.
⟡ hollow (https://github.com/Netflix/hollow) - Java library and comprehensive toolset for harnessing small to moderately sized in-memory datasets.
⟡ high-scale-lib (https://github.com/boundary/high-scale-lib) - Cliff Click's High Scale Library.
⟡ hppc (https://github.com/carrotsearch/hppc) - High Performance Primitive Collections.
⟡ injector (https://github.com/belliottsmith/injector) - A new Executor for Java.
⟡ java-concurrent-hash-trie-map (https://github.com/romix/java-concurrent-hash-trie-map) - Java port of a concurrent trie hash map implementation from Scala collections.
⟡ java-hll (https://github.com/aggregateknowledge/java-hll) - Java library for the HyperLogLog algorithm.
⟡ JavaFastPFOR (https://github.com/lemire/JavaFastPFOR) - Library to compress and uncompress arrays of integers very fast.
⟡ java-string-similarity (https://github.com/tdebatty/java-string-similarity) - String similarity and distance measures, including Levenshtein edit distance and sibblings, Jaro-Winkler, Longest Common Subsequence, cosine similarity etc.
⟡ JCTools (http://jctools.github.io/JCTools/) - Concurrent data structures currently missing from the JDK.
⟡ DSL-JSON (http://github.com/ngs-doo/dsl-json) - High performance JSON library with advanced compile-time databinding.
⟡ jsoniter (http://jsoniter.com/) - Claims to be the fastest JSON parser ever (copy of DSL-JSON).
⟡ jOOL (https://github.com/jOOQ/jOOL) - Useful extensions to Java 8 lambdas.
⟡ Koloboke (https://github.com/OpenHFT/Koloboke) - Java Collections til the last breadcrumb of memory and performance.
⟡ LevelDB (https://github.com/dain/leveldb) - Rewrite (port) of LevelDB in Java.
⟡ lightweight_trie (https://github.com/bryanduxbury/lightweight_trie) - A very memory-efficient trie (radix tree) implementation.
⟡ lmdbjni (https://github.com/deephacks/lmdbjni) - Java API to LMDB (HawtJNI) which is an ultra-fast, ultra-compact key-value embedded data store written in C.
⟡ lmdbjava (https://github.com/lmdbjava/lmdbjava) - Java API to LMDB (JNR) which is an ultra-fast, ultra-compact key-value embedded data store written in C.
⟡ low-gc-membuffers (https://github.com/cowtowncoder/low-gc-membuffers) - In-memory circular buffers that use direct ByteBuffers to minimize GC overhead.
⟡ lwjgl3 (https://github.com/LWJGL/lwjgl3) - Java library that enables cross-platform access to popular native APIs useful in the development of graphics (OpenGL), audio (OpenAL) and parallel computing (OpenCL) applications.
⟡ MapDB (http://www.mapdb.org) - Collections backed by off-heap or on-disk storage.
⟡ mph-table (https://github.com/indeedeng/mph-table) - Minimal Perfect Hash Tables are an immutable key/value store with efficient space utilization and fast reads.
⟡ mug (https://google.github.io/mug/) - A small, zero-dep functional util library originating from Google. 
⟡ netty-buffers (http://netty.io/wiki/using-as-a-generic-library.html#wiki-h2-1) - Memory buffer pool implementation similar to jemalloc.
⟡ ObjectLayout (http://objectlayout.org) - A layout-optimized Java data structure package.
⟡ ohc (https://github.com/snazy/ohc) - Java large off heap cache developed for Apache Cassandra 3.0.
⟡ okio (https://github.com/square/okio) - Modern Java IO library that do clever things to save CPU and memory.
⟡ onyx-java (https://github.com/onyx-platform/onyx-java) - Mirrors the Onyx Platform core API by providing a Java equivalent for each component of an Onyx workflow.
⟡ parquet (https://parquet.apache.org/) - Columnar storage format that uses the record shredding and assembly algorithm described in the Dremel paper.
⟡ PauselessHashMap (https://github.com/giltene/PauselessHashMap) - A java.util.HashMap compatible map that won't stall puts or gets when resizing.
⟡ pcollections (https://github.com/hrldcpr/pcollections) - A Persistent Java Collections Library.
⟡ protobuf (https://developers.google.com/protocol-buffers) - Google's data interchange format.
⟡ Quasar (http://www.paralleluniverse.co/quasar/) - Lightweight threads and actors for the JVM.
⟡ rtree (https://github.com/davidmoten/rtree) - Immutable in-memory R-tree and R-tree implementations in Java with reactive api.
⟡ RTree2D (https://github.com/Sizmek/rtree2d) - RTree2D is a 2D immutable R-tree with STR (Sort-Tile-Recursive) packing for ultra-fast nearest and intersection queries on plane and spherical surfaces.
⟡ Reactive Streams (http://www.reactive-streams.org/) - Standard for asynchronous stream processing with non-blocking back pressure.
⟡ Reactive Streams Utilities (https://github.com/lightbend/reactive-streams-utils) - Future standard utilities library for Reactive Streams.
⟡ RoaringBitmap (https://github.com/RoaringBitmap/RoaringBitmap) - A better compressed bitset in Java.
⟡ rollinghashjava (https://github.com/lemire/rollinghashjava) - Rolling hash functions in Java.
⟡ Reactor (http://projectreactor.io/) - Reactive data applications on the JVM for Java, Groovy, Clojure and other.
⟡ RxJava (https://github.com/ReactiveX/RxJava) - Library for composing asynchronous and event-based programs using observable sequences.
⟡ SmoothieMap (https://github.com/OpenHFT/SmoothieMap) - java.util.Map impl with worst put latencies more than 100 times smaller than java.util.HashMap.
⟡ Simple Binary Encoding (https://github.com/real-logic/simple-binary-encoding) - High Performance Message Codec.
⟡ splitmap (https://github.com/richardstartin/splitmap/) - A parallel bitmap implementation.
⟡ DataSketches (https://datasketches.github.io/) - A Java software library of stochastic streaming algorithms.
⟡ stormpot (https://github.com/chrisvest/stormpot) - A fast object pool for the JVM.
⟡ stream-lib (https://github.com/addthis/stream-lib) - A Java library for summarizing data in streams for which it is infeasible to store all events.
⟡ streamvbyte (https://github.com/lemire/streamvbyte) - Fast integer compression in C using the StreamVByte codec.
⟡ TraneIO (http://trane.io/) - High-performance implementation of the Future abstraction.
⟡ transducers-java (https://github.com/cognitect-labs/transducers-java) - Composable algorithmic transformations independent from the context of their input and output sources.
⟡ VarInt (https://github.com/bazelbuild/bazel/blob/master/src/main/java/com/google/devtools/build/lib/util/VarInt.java) - No-deps variable int implementation without deps (by Bazel).
⟡ vavr (http://www.vavr.io/) - Functional Library for Java 8+.
⟡ wire (https://github.com/square/wire) - Clean, lightweight protocol buffers for Android and Java.
⟡ Zero-Allocation-Hashing (https://github.com/OpenHFT/Zero-Allocation-Hashing) - Hashing any sequences of bytes in Java, including all kinds of primitive arrays, buffers, CharSequences and more.

Metaprogramming

Parsers, interpreters, compilers and source generation targeted for the JVM.

⟡ Antlr (http://www.antlr.org/) - Parser generator for reading, processing, executing, or translating structured text or binary files.
⟡ auto (https://github.com/google/auto) - A collection of source code generators for Java.
⟡ Apache Calcite (http://calcite.apache.org/docs/) - Dynamic data management framework and SQL parser plugin.
⟡ Checker Framework (http://types.cs.washington.edu/checker-framework/) - Compiler plug-ins that find bugs or verify their absence.
⟡ compile-testing (https://github.com/google/compile-testing) - Testing tools for javac and annotation processors.
⟡ derive4j (https://github.com/derive4j/derive4j) - Algebraic data types constructors, pattern-matching, morphisms, optics and typeclasses.
⟡ error-prone (https://github.com/google/error-prone) - Catch common Java mistakes as compile-time errors.
⟡ GHCVM (https://github.com/rahulmutt/ghcvm) - A Haskell to JVM compiler that supports GHC Haskell.
⟡ Graal (http://openjdk.java.net/projects/graal/) - New experimental just-in-time compiler for Java that is integrated with the HotSpot virtual machine.
⟡ grappa (https://github.com/fge/grappa) - Java fork of Parboiled. Write grammars with no preprocessing phase.
⟡ immutables (http://immutables.github.io/) - Generate simple, safe and consistent value objects.
⟡ javacc (https://javacc.java.net/) - Parser generator for use with Java.
⟡ javaparser (https://github.com/javaparser/javaparser) - Java 1.8 Parser and Abstract Syntax Tree for Java.
⟡ JavaPoet (https://github.com/square/javapoet) - A Java API for generating .java source files.
⟡ jparsec (https://github.com/jparsec/jparsec) - Builds mini parsers in pure Java a la Haskell Parsec.
⟡ JSweet (http://www.jsweet.org/) - A transpiler from Java to TypeScript/JavaScript.
⟡ MPS (https://www.jetbrains.com/mps/) - Design and build extensible DSLs and editors.
⟡ lombok (https://projectlombok.org/) - Reduce the amount of boilerplate code that is commonly written for Java classes.
⟡ parboiled (https://github.com/sirthias/parboiled) - Parsing of arbitrary input text based on parsing expression grammars.
⟡ Sulong (https://github.com/graalvm/sulong) - LLVM IR interpreter written in Java using Truffle and Graal.
⟡ TeaVM (https://github.com/konsoletyper/teavm) - Ahead-of-time translating compiler (transpiler) from Java bytecode to JavaScript.
⟡ Truffle (https://github.com/graalvm/truffle) - Framework for implementing languages as simple interpreters.
⟡ Xtext (https://eclipse.org/Xtext/) - Framework for development of programming languages and DSLs.

Native

Interconnecting JVM and native code 

⟡ hawtjni (https://github.com/fusesource/hawtjni) - A JNI code generator based on the JNI generator used in Eclipse SWT.
⟡ Java Grinder (https://github.com/mikeakohn/java_grinder) - Compile Java bytecode to microcontroller assembly.
⟡ j2v8 (https://github.com/eclipsesource/j2v8) - Java API for Google's V8 JavaScript engine.
⟡ JavaCPP (https://github.com/bytedeco/javacpp) - JavaCPP provides efficient access to native C++ inside Java.
⟡ jnr-ffi (https://github.com/jnr/jnr-ffi) - Load native libraries without writing JNI code by hand.
⟡ jssembly (https://github.com/dvx/jssembly) - Execution of native assembly from Java.
⟡ NuProcess (https://github.com/brettwooldridge/NuProcess) - A low-overhead, non-blocking I/O, external Process execution implementation for Java.
⟡ Project Panama (http://openjdk.java.net/projects/panama/) - Enriching the connections between the JVM and APIs used by C programmers.

Network

Tools for network programming, packet capture, monitoring, testing and resiliency.

⟡ Aeron (https://github.com/real-logic/Aeron) - Efficient reliable UDP unicast, UDP multicast, and IPC message transport.
⟡ armeria (https://github.com/line/armeria) - Asynchronous RPC/API client/server library built on top of Java 8, Netty 4.1, HTTP/2, and Thrift.
⟡ Chronicle-Network (https://github.com/OpenHFT/Chronicle-Network) - A High Performance Network library.
⟡ comcast (https://github.com/tylertreat/comcast) - Simulating shitty network connections.
⟡ gor (https://github.com/buger/gor) - HTTP traffic replay in real-time.
⟡ gRPC (http://www.grpc.io/) - A high performance, open source, general RPC framework that puts mobile and HTTP/2 first.
⟡ jRT (https://github.com/LatencyUtils/jRT) - Measures response time of a java application to socket-based requests.
⟡ JXIO (https://github.com/accelio/JXIO) - Java API over AccelIO (C library), a high-performance asynchronous reliable messaging and RPC library optimized for hardware acceleration.
⟡ K3PO (https://github.com/k3po/k3po) - Create arbitrary network traffic and behavior to certify whether a network endpoint behaves correctly.
⟡ muxy (https://github.com/mefellows/muxy) - Simulating real-world distributed system failures.
⟡ Netty (http://netty.io/) - Async event-driven network library for high performance protocol servers & clients.
⟡ okhttp (https://github.com/square/okhttp) - An HTTP+HTTP/2 client for Android and Java applications.
⟡ one-nio (https://github.com/odnoklassniki/one-nio) - library for building high performance Java servers.
⟡ proteus-java (https://github.com/netifi-proteus/proteus-java) - Proteus Java Client based on RSocket.
⟡ reactive-grpc (https://github.com/salesforce/reactive-grpc) - Reactive gRPC is a suite of libraries for using gRPC with Reactive Streams programming libraries.
⟡ RSocket (http://rsocket.io/) - RSocket is a binary protocol for use on byte stream transports such as TCP, WebSockets, and Aeron.
⟡ SimianArmy (https://github.com/Netflix/SimianArmy) - Resiliency tool that helps ensure that your applications can tolerate random instance failures.
⟡ pcap4j (https://github.com/kaitoy/pcap4j) - Java library for capturing, crafting, and sending packets using libpcap.
⟡ pig (https://github.com/rafael-santiago/pig) - A Linux packet crafting tool.
⟡ tcpdump (http://www.tcpdump.org/) - Packet analyzer for network traffic capture.
⟡ tcpflow (https://github.com/simsong/tcpflow) - Captures TCP connections flows in a way that is convenient for protocol analysis and debugging.
⟡ tcpreplay (https://github.com/appneta/tcpreplay) - Pcap editing and replay tools.

Nix tools

Useful nix tools when profiling the JVM and interaction with the host environment*
⟡ atoptool (http://www.atoptool.nl/) - Logging of system and process activity for long-term analysis, highlighting overloaded system.
⟡ bcc (https://github.com/iovisor/bcc) - Tools for BPF-based Linux IO analysis, networking, monitoring, and more.
⟡ Flame Graphs (http://www.brendangregg.com/flamegraphs.html) - Visualization of profiled software, allowing the most frequent code-paths to be identified quickly and accurately.
⟡ ioping (https://github.com/koct9i/ioping) - Simple disk I/0 latency measuring tool.
⟡ javap (http://docs.oracle.com/javase/8/docs/technotes/tools/unix/javap.html) - Disassembles class files into code that reflects the java bytecode.
⟡ jhat (http://docs.oracle.com/javase/8/docs/technotes/tools/unix/jhat.html) - Java Heap Analysis Tool
⟡ jhsdb (https://docs.oracle.com/javase/9/tools/jhsdb.htm) - Launch a postmortem debugger to analyze the content of a core-dump from a crashed JVM.
⟡ jinfo (http://docs.oracle.com/javase/8/docs/technotes/tools/unix/jinfo.html) - Prints configuration information for a given process.
⟡ jstack (http://docs.oracle.com/javase/8/docs/technotes/tools/unix/jstack.html) - Prints stack traces of threads for a given Java process.
⟡ jstat (https://docs.oracle.com/javase/8/docs/technotes/tools/unix/jstat.html) - Monitors GC and compiler statistics in the JVM.
⟡ hwloc (http://linux.die.net/man/7/hwloc) - Reports the structure of the processor, number of cores, hyperthreads and cache size.
⟡ likwid (https://github.com/RRZE-HPC/likwid) - Read hardware performance counters on Intel and AMD processors.
⟡ numactl (http://linux.die.net/man/8/numactl) - Control NUMA policy for processes or shared memory.
⟡ oprofile (http://oprofile.sourceforge.net/news/) - System-wide hardware performance monitoring with easy-to-use interface at low overhead.
⟡ perf (https://perf.wiki.kernel.org/index.php/Main_Page) - Linux profiling with performance counters.
⟡ perf-tools (https://github.com/brendangregg/perf-tools) - Performance analysis tools based on Linux perf_events (aka perf) and ftrace.
⟡ sysdig (http://www.sysdig.org/) - Capture system state and activity from a running Linux instance, then save, filter and analyze.
⟡ sysstat (http://sebastien.godard.pagesperso-orange.fr) - Performance monitoring tools for Linux.
⟡ taskset/process-affinity (https://www.glennklockwood.com/hpc-howtos/process-affinity.html) - Retrieve or set a processes’s CPU affinity.
⟡ tiptop (http://tiptop.gforge.inria.fr/) - Like top but also shows instructions per cycle (IPC).

Profilers

Tools that provide profiling and tracing information to aid program optimization

⟡ allocation-instrumenter (https://github.com/google/allocation-instrumenter) - Java agent that rewrites bytecode to instrument allocation sites.
⟡ aprof (https://github.com/Devexperts/aprof) - Java memory allocation profiler.
⟡ async-profiler (https://github.com/jvm-profiling-tools/async-profiler) - Sampling CPU profiler for Java featuring AsyncGetCallTrace + perf_events.
⟡ BTrace (https://github.com/jbachorik/btrace) - a safe, dynamic tracing tool for the Java platform.
⟡ Byteman (http://byteman.jboss.org/) - tracing, monitoring and testing tool for Java
⟡ bytestacks (https://github.com/cl4es/bytestacks) - Turn JVM bytecode execution into flame graphs. 
⟡ Chronon (http://chrononsystems.com) - Record your entire java program. Replay on any machine.
⟡ GCeasy (http://gceasy.io/) - Machine learning guided Garbage collection log analysis tool. Auto-detect problems in the JVM GC logs and recommend solutions to it.
⟡ GCViewer (https://github.com/chewiebug/GCViewer) - GCViewer is a tool that visualizes verbose GC output.
⟡ grav (https://github.com/epickrram/grav) - A collection of tools to help visualise process execution.
⟡ hawkshaw (https://github.com/jClarity/hawkshaw) - Tools for tracking down memory / JVM problems & generating predictable-as-possible VM behaviour.
⟡ HdrHistogram (http://hdrhistogram.github.io/HdrHistogram/) - A Histogram that supports recording and analyzing sampled data value counts.
⟡ hdrhistogram-metrics-reservoir (https://bitbucket.org/marshallpierce/hdrhistogram-metrics-reservoir) - A Metrics Reservoir implementation backed by HdrHistogram.
⟡ HdrLogProcessing (https://github.com/nitsanw/HdrLogProcessing) - Utilities for HDR Histogram logs manipulation.
⟡ heapster (https://github.com/mariusae/heapster) - Production heap profiling for the JVM.
⟡ honest-profiler (https://github.com/RichardWarburton/honest-profiler) - Sampling JVM profiler without the safepoint sample bias.
⟡ jamm (https://github.com/jbellis/jamm) - Measure actual object memory use including JVM overhead.
⟡ Java Flight Recorder (JFR)
 (http://www.oracle.com/technetwork/java/javaseproducts/mission-control/java-mission-control-1998576.html) - Tool for collecting diagnostic and profiling data about a running Java application with almost no performance overhead.
⟡ java-sizeof (https://github.com/dweiss/java-sizeof) - Memory consumption estimator for Java.
⟡ jcstress (http://openjdk.java.net/projects/code-tools/jcstress/) - Experimental harness and tests to aid the research in the correctness of concurrency support in the JVM, class libraries, and hardware.
⟡ jfr-flame-graph (https://github.com/chrishantha/jfr-flame-graph) - Converting JFR Method Profiling Samples to FlameGraph compatible format.
⟡ jfr-report-tool (https://github.com/lhotari/jfr-report-tool) - Tool for creating reports from Java Flight Recorder dumps.
⟡ jitwatch (https://github.com/AdoptOpenJDK/jitwatch) - Log analyser / visualiser for Java HotSpot JIT compiler.
⟡ jitwatch-intellij (https://github.com/yole/jitwatch-intellij) - JITWatch plugin for IntelliJ IDEA.
⟡ jHiccup (http://www.azul.com/jhiccup/) - jHiccup is an open source tool designed to measure the pauses and stalls associated with an application’s underlying Java runtime platform.
⟡ jmh (http://openjdk.java.net/projects/code-tools/jmh/) - Micro benchmarks written in Java and other languages targetting the JVM.
⟡ jmh-compare-gui (https://github.com/akarnokd/jmh-compare-gui) - GUI for comparing JMH results.
⟡ JOL (http://openjdk.java.net/projects/code-tools/jol/) - Analyze actual object layout schemes, footprint, and references in JVMs.
⟡ JProfiler (https://www.ej-technologies.com/products/jprofiler/overview.html) - Helps resolve performance bottlenecks, pin down memory leaks and understand threading issues.
⟡ JVMTI (https://docs.oracle.com/javase/8/docs/technotes/guides/jvmti/) - Provide a native API to inspect the state and to control the execution of applications running in the JVM.
⟡ jvmtop (https://github.com/patric-r/jvmtop) - Lightweight console application to monitor running jvms on a machine in top-like manner.
⟡ jvm-profiler (https://github.com/uber-common/jvm-profiler) - Java Agent to collect various metrics and stacktraces for Hadoop/Spark JVM processes in a distributed way.
⟡ MAT (https://eclipse.org/mat/) - Java heap analyzer that help find memory leaks and reduce memory consumption.
⟡ leakcanary (https://github.com/square/leakcanary) - A memory leak detection library for Android and Java.
⟡ metrics (http://metrics.dropwizard.io/) - Measure the behavior of critical components in production environment.
⟡ micrometer (https://github.com/micrometer-metrics/micrometer) - An application metrics facade for the most popular monitoring tools.
⟡ osquery (https://osquery.io/) - osquery is an instrumentation framework that expose the operating system as a high-performance relational database.
⟡ Overseer (http://www.peternier.com/projects/overseer/overseer.php) - Low-Level Hardware Monitoring and Management for Java.
⟡ OpenTracing (http://opentracing.io/) - A vendor-neutral open standard for distributed tracing.
⟡ perf-map-agent (https://github.com/jrudolph/perf-map-agent) - Generate method mappings to use with the linux perf tool.
⟡ perfj (https://github.com/coderplay/perfj) - Linux perf for java programs.
⟡ polarbear (https://github.com/Cue/polarbear) - A tool to help diagnose OutOfMemoryError conditions.
⟡ Riemann JVM Profiler (https://github.com/riemann/riemann-jvm-profiler) - JVM agent which sends function-level profiler telemetry to a Riemann server for analysis, visualization, and storage.
⟡ statsd-jvm-profiler (https://github.com/etsy/statsd-jvm-profiler) - JVM agent profiler that sends profiling data to StatsD.
⟡ Swiss Java Knife (https://github.com/aragozin/jvm-tools) - Small set of tools for JVM troublshooting, monitoring and profiling.
⟡ Takipi (https://www.takipi.com/) - Tells you when and why code breaks in production.
⟡ Tracer (https://github.com/zalando/tracer) - Manages custom trace identifiers and carries them through distributed systems.
⟡ YourKit (https://www.yourkit.com/) - Fully featured, easy to use, low overhead profiler.
⟡ Zipkin (https://github.com/openzipkin/zipkin) - A distributed tracing system gather timing data for disparate services developed by Twitter.


Runtimes

Tools for managing jvm runtime processes
⟡ Capsule (https://github.com/puniverse/capsule) - Dead-Simple Packaging and Deployment for JVM Apps.
⟡ CRaSH (http://www.crashub.org/) - The shell for the Java Platform.
⟡ Drip (https://github.com/ninjudd/drip) - Fast JVM launching without the hassle of persistent JVMs.
⟡ HotswapAgent (https://github.com/HotswapProjects/HotswapAgent) - Redefine classes at runtime and skip the redeploy process.
⟡ jvmkill (https://github.com/airlift/jvmkill) - Agent that forcibly terminates the JVM when it is unable to allocate memory or create a thread.
⟡ Nailgun (http://martiansoftware.com/nailgun/) - Nailgun is a client, protocol, and server for running Java programs from the command line without incurring the JVM startup overhead.

Virtual Machines

Virtual machines that implement the JVM specification or parts of it.
⟡ Avian (https://github.com/ReadyTalk/avian) - Lightweight highly portable JVM with an option for AOT compilation.
⟡ Dalvik (https://source.android.com/devices/tech/dalvik/) - Android runtime (ART) is the managed runtime used by applications and some system services on Android.
⟡ DCEVM (http://dcevm.github.io) - Modification of Java HotSwap VM with unlimited support for reloading classes at runtime.
⟡ HotSpot (http://openjdk.java.net/groups/hotspot/) - HotSpot virtual machine maintained and distributed by Oracle Corporation.
⟡ IBM J9 (http://www.ibm.com/developerworks/java/jdk/) - JVM developed by IBM.
⟡ Eclipse OpenJ9 (https://github.com/eclipse/openj9) - Eclipse OpenJ9.
⟡ J2ObjC (https://github.com/google/j2objc) - Translator from Java source to Objective-C code. Keeps shared code between iOS native apps and Android native apps. 
⟡ jvm.go (https://github.com/zxh0/jvm.go) - A JVM written in Go.
⟡ ParparVM (https://github.com/codenameone/CodenameOne/tree/master/vm) - An Open Source Java bytecode to C translator for iOS native development. Designed as a part of the Codename One (https://www.codenameone.com/) WORA for mobile project.
⟡ MobiDevelop's RoboVM Fork (https://github.com/MobiVM/robovm) - Ahead of time compiler for JVM bytecode targeting iOS, Mac OSX and Linux.
⟡ Zing (https://www.azul.com/products/zing/) - The only JVM that eliminates Java garbage collection pauses for large heap sizes.
⟡ Zulu (https://www.azul.com/products/zulu/) - The only certified multi-platform build of OpenJDK: Free, 100% open source Java.

                                                                                                                      Resources

Documentation

Documentation related to JVM
⟡ TCP Tracepoints (http://www.brendangregg.com/blog/2018-03-22/tcp-tracepoints.html) Linux bcc/BPF using tcplife by Brendan Gregg
⟡ Linux tracing workshop (https://github.com/goldshtn/linux-tracing-workshop) - JVM monitoring with BPF, examples and hands-on labs for Linux tracing tools workshops.
⟡ JVM Anatomy Park (https://shipilev.net/jvm-anatomy-park/) - mini-post series where every post goes deep for only a single topic by Aleksey Shipilёv.
⟡ Coordinated Omission problem (https://groups.google.com/forum/#!msg/mechanical-sympathy/icNZJejUHfE/BfDekfBEs_sJ) - Discussion on Mechanical Sympathy.
⟡ False sharing (http://mechanical-sympathy.blogspot.se/2011/07/false-sharing.html) - Threads impact the performance of each other while modifying independent variables sharing the same cache line. Martin Thompson.
⟡ The JVM specification (https://docs.oracle.com/javase/specs/jvms/se8/jvms8.pdf) - The Java Virtual
Machine Specification Java SE 8 Edition.
⟡ The Java Memory Model (http://www.cs.umd.edu/~pugh/java/memoryModel/) - Starting point for discussions of and information concerning the Java Memory Model.
⟡ The JSR-133 Cookbook for Compiler Writers (http://gee.cs.oswego.edu/dl/jmm/cookbook.html) - Unofficial guide to implementing the new Java Memory Model (JMM) specified by JSR-133.
⟡ Garbage Collection Tuning Guide (http://docs.oracle.com/javase/8/docs/technotes/guides/vm/gctuning/) - HotSpot Virtual Machine Garbage Collection Tuning Guide.
⟡ Safepoints (http://psy-lob-saw.blogspot.se/2014/03/where-is-my-safepoint.html) - Where is my safepoint? Nitsan Wakart.
⟡ Topics in High-Performance Messaging (https://www.informatica.com/downloads/1568_high_perf_messaging_wp/Topics-in-High-Performance-Messaging.htm) - Design decisions, experience and constraints explained in high performance messaging systems.
⟡ Top 10 Performance Mistakes (http://www.infoq.com/articles/top-10-performance-mistakes) - Digest of the top 10 performance related mistakes Martin Thompson has seen in production.
⟡ The USE method (http://www.brendangregg.com/usemethod.html) - The Utilization Saturation and Errors (USE) Method is a methodology for analyzing the performance of any system. Brendan Gregg.
⟡ An introduction to distributed systems (https://github.com/aphyr/distsys-class) - Kyle Kingsbury (author of Jepsen).
⟡ Using JDK 9 Memory Order Modes (http://gee.cs.oswego.edu/dl/html/j9mm.html) - For expert programmers familiar with Java concurrency, but unfamiliar with the memory order modes available in JDK 9 provided by VarHandles.
⟡ CPU Utilization is Wrong (http://www.brendangregg.com/blog/2017-05-09/cpu-utilization-is-wrong.html) - Measure instructions per cycle (IPC) for CPU utilization. Brendan Gregg.
⟡ Linux Load Averages: Solving the Mystery (http://www.brendangregg.com/blog/2017-08-08/linux-load-averages.html) - Brendan Gregg.
⟡ What every programmer should know about solid-state drives (http://codecapsule.com/2014/02/12/coding-for-ssds-part-6-a-summary-what-every-programmer-should-know-about-solid-state-drives/) - Emmanuel Goossaert.
⟡ Quick Tips for Fast Code on the JVM (https://gist.github.com/djspiewak/464c11307cabc80171c90397d4ec34ef) - Daniel Spiewak.
Communities

Active discussions.

⟡ concurrency-interest (http://altair.cs.oswego.edu/mailman/listinfo/concurrency-interest) - Discussion list for JSR-166.
⟡ hotspot-compiler-dev (http://mail.openjdk.java.net/mailman/listinfo/hotspot-compiler-dev) - Technical discussion about the development of the HotSpot bytecode compilers.
⟡ hotspot-dev (http://mail.openjdk.java.net/mailman/listinfo/hotspot-dev) - HotSpot development mailing list.
⟡ hotspot-gc-dev (http://mail.openjdk.java.net/mailman/listinfo/hotspot-gc-dev) - Technical discussion about the development of the HotSpot garbage collectors.
⟡ mechanical-sympathy (https://groups.google.com/forum/#!forum/mechanical-sympathy) - Discussing how to code sympathetically to and measure the underlying stack/platform so good performance can be extracted.
⟡ Performance Java User's Group (https://plus.google.com/u/0/communities/107178245817384004088/) - For expert Java developers who want to push their systems to the next level
⟡ Virtual Machine Meetup 2017 (http://vmmeetup.github.io/2017/) - Venue for discussing the latest research and developments in the area of managed language execution. 

Media

Videos, podcasts and other media related to JVMs
⟡ FOSDEM 2018 (https://fosdem.org/2018/schedule/track/free_java/) - FOSDEM 2018 Free Java devroom.
⟡ JFokus 2018 (https://www.youtube.com/playlist?list=PL2ekzZZrxVUkhrcMKuPMbiKoghc777plr) - The GC edition. Shenandoah, ZGC, Zing, Fibers, Falcon etc.
⟡ G1 Garbage Collector in Java 8/9 (http://nighthacking.com/g1-gc-with-kirk-pepperdine/) - Kirk Pepperdine.
⟡ Extreme Profiling: Digging Into Hotspots (https://youtu.be/7PkkxDaFDj8?list=PLKuh52zVrL6l6jzeSwNce77yLdfKmHAgD) - Nitsan Wakart.
⟡ Java vs. C Performance (http://www.infoq.com/presentations/java-vs-c-performance) - Cliff Click.
⟡ Why JNI is slow? (https://www.youtube.com/watch?v=LoyBTqkSkZk) - Cliff Click
⟡ A Crash Course in Modern Hardware (https://www.youtube.com/watch?v=OFgxAFdxYAQ) - Cliff Click
⟡ Java Profiling from the Ground Up (https://www.youtube.com/watch?v=_6vJyciXkwo) - Nitsan Wakart.
⟡ The Illusion of Execution (https://www.youtube.com/watch?v=3g9R-RVIkOE) - Nitsan Wakart.
⟡ Mythbusting Modern Hardware to Gain 'Mechanical Sympathy' (https://www.youtube.com/watch?v=MC1EKLQ2Wmg) - Martin Thompson.
⟡ Designing for Performance (https://www.youtube.com/watch?v=fDGWWpHlzvw) - Martin Thompson.
⟡ How NOT to Measure Latency (https://www.youtube.com/watch?v=lJ8ydIuPFeU) - Gil Tene.
⟡ JVM Language Summit 2015 (http://openjdk.java.net/projects/mlvm/jvmlangsummit/) - JVM Language Summit 2015.
⟡ JVM Language Summit 2016 (https://www.youtube.com/playlist?list=PLX8CzqL3ArzUY6rQAQTwI_jKvqJxrRrP_) - JVM Language Summit 2016.
⟡ JVM Language Summit 2017 (https://www.youtube.com/playlist?list=PLX8CzqL3ArzXJ2EGftrmz4SzS6NRr6p2n) - JVM Language Summit 2017.
⟡ Bits of advice for VM writers (https://www.youtube.com/watch?v=vzzABBxo44g) - Cliff Click.
⟡ Understanding Java garbage collection ... (https://www.youtube.com/watch?v=_e5hujoTkgY) - Gil Tene.
⟡ Faster Object Arrays (https://www.youtube.com/watch?v=bZuPTCaciLU) - Gil Tene at GOTO Conferences.
⟡ Java Memory Model Pragmatics (https://www.youtube.com/watch?v=TxqsKzxyySo) - Aleksey Shipilev.
⟡ With GC Solved, What Else Makes a JVM Pause? (https://www.youtube.com/watch?v=Y39kllzX1P8) - John Cuthbertson.
⟡ JVM Mechanics (https://vimeo.com/120533011) - Douglas Hawkins.
⟡ Give me 15 minutes and I'll change your view of Linux tracing (https://www.youtube.com/watch?v=GsMs3n8CB6g) - Brendan Gregg.
⟡ Kernel Recipes 2017: Performance Analysis with BPF (https://www.slideshare.net/brendangregg/kernel-recipes-2017-performance-analysis-with-bpf) - Brendan Gregg.
⟡ Shenandoah deep talk (https://shipilev.net/talks/vmm-Sep2017-shenandoah.pdf) - Aleksey Shipilëv slightly-deeper-than-usual Shenandoah talk from Virtual Machine Meetup 2017.
⟡ Shenandoah: The Garbage Collector That Could (https://www.youtube.com/watch?v=VCeHkcwfF9Q) - Aleksey Shipilev - Devoxx 2017/11
⟡ Analyzing and Debugging the Java HotSpot VM at the OS Level (https://www.youtube.com/watch?v=k7IX_diKCEo) - Volker Simonis.
⟡ Cliff Click podcast 2017/09/16 (http://www.cliffc.org/blog/2017/09/16/programming-and-performance-intro/) - Programming and Performance Intro.
⟡ Cliff Click podcast 2017/09/16 (http://www.cliffc.org/blog/2017/09/16/of-bugs-and-coding-styles/) - Bugs and Coding Styles.
⟡ Cliff Click podcast 2017/09/18 (http://www.cliffc.org/blog/2017/09/18/java-vs-cc-the-podcast/) - Java vs C/C++.
⟡ Cliff Click podcast 2017/09/21 (http://www.cliffc.org/blog/2017/09/21/debugging-data-races/) - Debugging Data Races.
⟡ Cliff Click podcast 2017/09/24 (http://www.cliffc.org/blog/2017/09/24/fast-bytecodes-for-funny-languages/) - Fast Bytecodes for Funny Languages.
⟡ Cliff Click podcast 2017/09/28 (http://www.cliffc.org/blog/2017/09/28/struct-of-arrays-vs-array-of-structs/) - Struct of Arrays vs Array of Structs.
⟡ Cliff Click podcast 2017/10/04 (http://www.cliffc.org/blog/2017/10/04/the-3-hardest-problems-in-programming/) - The 3 Hardest Problems in Programming.
⟡ Cliff Click podcast 2017/11/05 (http://cliffc.org/blog/2017/11/05/modern-hardware-performance-cache-lines/) - Modern Hardware Performance and Cache Lines.
⟡ Cliff Click podcast 2017/11/09 (http://cliffc.org/blog/2017/11/09/queuing-in-practice/) - Queuing In Practice.
⟡ Which technique do programming language parsers and interpreters use? (https://www.quora.com/Which-technique-do-programming-language-parsers-and-interpreters-use/answer/Cliff-Click-1?srid=dZAx) - Cliff Click.
⟡ Everything about Stack Traces and Heap Dumps (https://vimeo.com/233820012) - Andrei Pangin.
⟡ Fast and safe production monitoring of JVM with BPF tools (http://s.sashag.net/velny17-jvm) - Sasha Goldshtein.
⟡ The Future of the Linux Page Cache (https://www.youtube.com/watch?time_continue=1&v=xxWaa-lPR-8) - Matthew Wilcox.

People

People that share hard-earned, often undocumented, knowledge and data of the inner workings of the JVM
⟡ Aleksey Shipilëv (http://shipilev.net/) - Developing Oracle/Open JDK/Hotspot and other Java-related technologies.
⟡ Andrey Breslav (https://twitter.com/abreslav) - Lead Language Designer of Kotlin @ JetBrains.
⟡ Brian Goetz (https://twitter.com/BrianGoetz) - Java Language Architect at Oracle.
⟡ Ben Christensen (https://twitter.com/benjchristensen) - Facebook, Netflix, Apple engineering.
⟡ Brendan Gregg (http://www.brendangregg.com) - Cloud performance, kernel engineer, speaker, author.
⟡ Charles Nutter (https://twitter.com/headius) - JRuby guy.
⟡ Claes Redestad (https://twitter.com/cl4es) - Working with OpenJDK stuff @ Oracle.
⟡ Cliff Click (http://www.cliffc.org/blog/) - Creator of the HotSpot Server Compiler.
⟡ Dave Dice (https://blogs.oracle.com/dave/) - Senior research scientist in the Scalable Synchronization Research Group within Oracle.
⟡ Dávid Karnok (http://akarnokd.blogspot.se/) - RxJava committer that blogs about advanced RxJava.
⟡ Doug Lea (http://g.oswego.edu/) - Author of the Java memory model.
⟡ Gil Tene (https://twitter.com/giltene) - Azul Systems.
⟡ Heinz Kabutz (https://twitter.com/heinzkabutz) - Author of 250+ Java Specialists' Newsletters.
⟡ Ivan Krylov (https://twitter.com/JohnWings) - JVM expert.
⟡ Jake Wharton (https://twitter.com/JakeWharton) - Square, Google, open source hacker.
⟡ John Rose (https://blogs.oracle.com/jrose/) - HotSpot developer.
⟡ Jonas Bonér (https://twitter.com/jboner) - Founder & CTO of Lightbend.
⟡ Lukas Eder (https://twitter.com/lukaseder) - Blogger. Author of JOOQ.
⟡ Marcus Lagergren (https://twitter.com/lagergren) - Java language team alumnus.
⟡ Mark Reinhold (https://twitter.com/mreinhold) - Chief Architect, Java Platform Group, Oracle.
⟡ Martin Thompson (http://mechanical-sympathy.blogspot.se/) - Pasty faced performance gangster.
⟡ Martijn Verburg (https://twitter.com/karianna) - Java Champion.
⟡ Kirk Pepperdine (https://twitter.com/javaperftuning) - Working in high performance and distributed computing for nearly 20 years.
⟡ Nitsan Wakart (http://psy-lob-saw.blogspot.se/2014/03/where-is-my-safepoint.html) - Azul Systems.
⟡ Norman Maurer (https://twitter.com/normanmaurer) - Netty developer.
⟡ Paul Phillips (https://twitter.com/contrarivariant) - Forever undisputed SLOC Scala compiler dev.
⟡ Per Liden (https://twitter.com/perliden) - Hacking on the HotSpot JVM at Oracle.
⟡ Peter Lawrey (https://twitter.com/PeterLawrey) - Innovative developer of high performance Java systems for competitive advantage.
⟡ Rafael Winterhalter (https://twitter.com/rafaelcodes) - Author of ByteBuddy.
⟡ Richard Warburton (https://twitter.com/RichardWarburto) - Developer, Speaker, Author.
⟡ Richard Startin (http://richardstartin.uk/) - Performance Analyst, developer, blogger.
⟡ Ron Pressler (https://twitter.com/pressron) - Parallel Universe. Leading Fibers and Continuations for the JVM.
⟡ Stephen Colebourne (https://twitter.com/jodastephen) - Java Champion. Occasional blogger and speaker. Best known for Joda projects and JSR-310.
⟡ Todd L. Montgomery (https://twitter.com/toddlmontgomery) - Ex-CTO, Ex-NASA researcher, network geek, messaging middleware designer.
⟡ Stéphane Maldini (https://twitter.com/smaldini) - Project Reactor Lead @Pivotal.
⟡ Stuart Marks (https://twitter.com/stuartmarks) - Doctor Deprecator. Java/JDK/OpenJDK developer 
⟡ Vladimir Ivanov (https://twitter.com/iwan0www) - hacking HotSpot JVM @ Oracle.
⟡ Viktor Klang (https://twitter.com/viktorklang) - Deputy CTO at Typesafe Inc.


                                                                                                                     Contributing

Contributions are very welcome!

Please have a look at contributing.md (https://github.com/deephacks/awesome-jvm/blob/master/contributing.md) for guidelines.

jvm Github: https://github.com/deephacks/awesome-jvm