Add a docs directory and move the third-party add-ons page here.

docs/third_party.md

+# Third-Party Add-ons for Protocol Buffers
+
+This page lists code related to Protocol Buffers which is developed and maintained by third parties.  You may find this code useful, but note that **these projects are not affiliated with or endorsed by Google (unless explicitly marked)**; try them at your own risk.  Also note that many projects here are in the early stages of development and not production-ready.
+
+If you have a project that should be listed here, please [send us a pull request](https://github.com/google/protobuf/pulls) to update this page.
+
+## Programming Languages
+
+These are projects we know about implementing Protocol Buffers for other programming languages:
+* Action Script: http://code.google.com/p/protobuf-actionscript3/
+* Action Script: https://code.google.com/p/protoc-gen-as3/
+* Action Script: https://github.com/matrix3d/JProtoc
+* C: https://github.com/protobuf-c/protobuf-c
+* C: http://koti.kapsi.fi/jpa/nanopb/
+* C: https://github.com/cloudwu/pbc/
+* C: https://github.com/haberman/upb/wiki
+* C: https://github.com/squidfunk/protobluff
+* C++: https://github.com/google/protobuf (Google-official implementation)
+* C/C++: http://spbc.sf.net/
+* C#: http://code.google.com/p/protobuf-csharp-port
+* C#: http://code.google.com/p/protosharp/
+* C#: https://silentorbit.com/protobuf/
+* C#/.NET/WCF/VB: http://code.google.com/p/protobuf-net/
+* Clojure: http://github.com/ninjudd/clojure-protobuf
+* Common Lisp: http://www.prism.gatech.edu/~ndantam3/docs/s-protobuf/
+* Common Lisp: http://github.com/brown/protobuf
+* D: https://github.com/msoucy/dproto
+* D: http://256.makerslocal.org/wiki/index.php/ProtocolBuffer
+* D: https://github.com/opticron/ProtocolBuffer
+* Dart: https://github.com/dart-lang/dart-protobuf (runtime) https://github.com/dart-lang/dart-protoc-plugin (code generator)
+* Delphi: http://sourceforge.net/projects/protobuf-delphi/
+* Delphi: http://fundementals.sourceforge.net/dl.html
+* Elixir: https://github.com/jeremyong/exprotoc
+* Erlang: http://github.com/ngerakines/erlang_protobuffs/tree/master
+* Erlang: http://piqi.org/
+* Erlang: https://code.google.com/p/protoc-gen-erl/
+* Erlang: https://github.com/basho/erlang_protobuffs
+* Go: https://github.com/golang/protobuf (Google-official implementation)
+* Go: http://code.google.com/p/goprotobuf/
+* Go: https://github.com/akunspy/gopbuf
+* Haskell: http://hackage.haskell.org/package/hprotoc
+* Haxe: https://github.com/Atry/protoc-gen-haxe
+* Java: https://github.com/google/protobuf (Google-official implementation)
+* Java/Android: https://github.com/square/wire
+* Java ME: http://code.google.com/p/protobuf-javame/
+* Java ME: http://swingme.sourceforge.net/encode.shtml
+* Java ME: http://github.com/ponderingpanda/protobuf-j2me
+* Java ME: http://code.google.com/p/protobuf-j2me/
+* Javascript: http://code.google.com/p/protobuf-js/
+* Javascript: http://github.com/sirikata/protojs
+* Javascript: https://github.com/dcodeIO/ProtoBuf.js
+* Javascript: http://code.google.com/p/protobuf-for-node/
+* Javascript: http://code.google.com/p/protostuff/
+* Julia: https://github.com/tanmaykm/ProtoBuf.jl
+* Lua: http://code.google.com/p/protoc-gen-lua/
+* Lua: http://github.com/indygreg/lua-protobuf
+* Lua: https://github.com/Neopallium/lua-pb
+* Matlab: http://code.google.com/p/protobuf-matlab/
+* Mercury: http://code.google.com/p/protobuf-mercury/
+* Objective C: http://code.google.com/p/protobuf-objc/
+* Objective C: https://github.com/alexeyxo/protobuf-objc
+* OCaml: http://piqi.org/
+* Perl: http://groups.google.com/group/protobuf-perl
+* Perl: http://search.cpan.org/perldoc?Google::ProtocolBuffers
+* Perl/XS: http://code.google.com/p/protobuf-perlxs/
+* PHP: http://code.google.com/p/pb4php/
+* PHP: https://github.com/allegro/php-protobuf/
+* PHP: https://github.com/chobie/php-protocolbuffers
+* PHP: http://drslump.github.com/Protobuf-PHP
+* Prolog: http://www.swi-prolog.org/pldoc/package/protobufs.html
+* Python: https://github.com/google/protobuf (Google-official implementation)
+* Python: http://eigenein.github.com/protobuf/
+* R: http://cran.r-project.org/package=RProtoBuf
+* Ruby: http://code.google.com/p/ruby-protobuf/
+* Ruby: http://github.com/mozy/ruby-protocol-buffers
+* Ruby: https://github.com/bmizerany/beefcake/tree/master/lib/beefcake
+* Ruby: https://github.com/localshred/protobuf
+* Rust: https://github.com/stepancheg/rust-protobuf/
+* Scala: http://github.com/jeffplaisance/scala-protobuf
+* Scala: http://code.google.com/p/protobuf-scala
+* Scala: https://github.com/SandroGrzicic/ScalaBuff
+* Scala: http://trueaccord.github.io/ScalaPB/
+* Swift: https://github.com/alexeyxo/protobuf-swift
+* Vala: https://launchpad.net/protobuf-vala
+* Visual Basic: http://code.google.com/p/protobuf-net/
+
+## RPC Implementations
+
+GRPC (http://www.grpc.io/) is Google's RPC implementation for Protocol Buffers. There are other third-party RPC implementations as well.  Some of these actually work with Protocol Buffers service definitions (defined using the `service` keyword in `.proto` files) while others just use Protocol Buffers message objects.
+
+* https://github.com/grpc/grpc (C++, Node.js, Python, Ruby, Objective-C, PHP, C#, Google-official implementation)
+* http://zeroc.com/ice.html (Multiple languages)
+* http://code.google.com/p/protobuf-net/ (C#/.NET/WCF/VB)
+* https://launchpad.net/txprotobuf/ (Python)
+* https://github.com/modeswitch/protobuf-rpc (Python)
+* http://code.google.com/p/protobuf-socket-rpc/ (Java, Python)
+* http://code.google.com/p/proto-streamer/ (Java)
+* http://code.google.com/p/server1/ (C++)
+* http://deltavsoft.com/RcfUserGuide/Protobufs (C++)
+* http://code.google.com/p/protobuf-mina-rpc/ (Python client, Java server)
+* http://code.google.com/p/casocklib/ (C++)
+* http://code.google.com/p/cxf-protobuf/ (Java)
+* http://code.google.com/p/protobuf-remote/ (C++/C#)
+* http://code.google.com/p/protobuf-rpc-pro/ (Java)
+* https://code.google.com/p/protorpc/ (Go/C++)
+* https://code.google.com/p/eneter-protobuf-serializer/ (Java/.NET)
+* http://www.deltavsoft.com/RCFProto.html (C++/Java/Python/C#)
+* https://github.com/robbinfan/claire-protorpc (C++)
+* https://github.com/BaiduPS/sofa-pbrpc (C++)
+* https://github.com/ebencheung/arab (C++)
+* http://code.google.com/p/protobuf-csharp-rpc/ (C#)
+* https://github.com/thesamet/rpcz (C++/Python, based on ZeroMQ)
+* https://github.com/w359405949/libmaid (C++, Python)
+* https://github.com/madwyn/libpbrpc (C++)
+
+## Other Utilities
+
+There are miscellaneous other things you may find useful as a Protocol Buffers developer.
+
+* [NetBeans IDE plugin](http://code.google.com/p/protobuf-netbeans-plugin/)
+* [Wireshark/Ethereal packet sniffer plugin](http://code.google.com/p/protobuf-wireshark/)
+* [Alternate encodings (JSON, XML, HTML) for Java protobufs](http://code.google.com/p/protobuf-java-format/)
+* [Another JSON encoder/decoder for Java](https://github.com/sijuv/protobuf-codec)
+* [Editor for serialized protobufs](http://code.google.com/p/protobufeditor/)
+* [Intellij IDEA plugin](http://github.com/nnmatveev/idea-plugin-protobuf)
+* [TextMate syntax highlighting](http://github.com/michaeledgar/protobuf-tmbundle)
+* [Oracle PL SQL plugin](http://code.google.com/p/protocol-buffer-plsql/)
+* [Eclipse editor for protobuf (from Google)](http://code.google.com/p/protobuf-dt/)
+* [C++ Builder compatible protobuf](https://github.com/saadware/protobuf-cppbuilder)
+* Maven Protocol Compiler Plugin
+    * https://github.com/sergei-ivanov/maven-protoc-plugin/
+    * http://igor-petruk.github.com/protobuf-maven-plugin/
+    * http://code.google.com/p/maven-protoc-plugin/
+    * https://github.com/os72/protoc-jar-maven-plugin
+* [Documentation generator plugin (Markdown/HTML/DocBook/...)](https://github.com/estan/protoc-gen-doc)
+* [DocBook generator for .proto files](http://code.google.com/p/protoc-gen-docbook/)
+* [Protobuf for nginx module](https://github.com/dbcode/protobuf-nginx/)
+* [RSpec matchers and Cucumber step defs for testing Protocol Buffers](https://github.com/connamara/protobuf_spec)
+* [Sbt plugin for Protocol Buffers](https://github.com/Atry/sbt-cppp)
+* [Gradle Protobuf Plugin](https://github.com/aantono/gradle-plugin-protobuf)
+* [Multi-platform executable JAR and Java API for protoc](https://github.com/os72/protoc-jar)
+* [Python scripts to convert between Protocol Buffers and JSON](https://github.com/NextTuesday/py-pb-converters)
+* [Visual Studio Language Service support for Protocol Buffers](http://visualstudiogallery.msdn.microsoft.com/4bc0f38c-b058-4e05-ae38-155e053c19c5)
+* [C++ library for serialization/de-serialization between Protocol Buffers and JSON.](https://github.com/yinqiwen/pbjson)
+* [ProtoBuf with Java EE7 Expression Language 3.0; pure Java ProtoBuf Parser and Builder.](https://github.com/protobufel/protobuf-el)
+* [Notepad++ Syntax Highlighting for .proto files](https://github.com/chai2010/notepadplus-protobuf)
+* [Linter for .proto files](https://github.com/ckaznocha/protoc-gen-lint)