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libs/protobuf/java/protoc/README.md

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+# Publish pre-compiled protoc artifacts
+``protoc`` is the compiler for ``.proto`` files. It generates language bindings
+for the messages and/or RPC services from ``.proto`` files.
+
+Because ``protoc`` is a native executable, the scripts under this directory
+publish a ``protoc`` executable (a.k.a. artifact) to Maven repositories. The
+artifact can be used by build automation tools so that users would not need to
+compile and install ``protoc`` for their systems.
+
+If you would like us to publish protoc artifact for a new platform, please
+open an issue to request it.
+
+## Maven Location
+The published protoc artifacts are available on Maven here:
+
+    https://repo.maven.apache.org/maven2/com/google/protobuf/protoc/
+
+## Versioning
+The version of the ``protoc`` artifact must be the same as the version of the
+Protobuf project.
+
+## Artifact name
+The name of a published ``protoc`` artifact is in the following format:
+``protoc-<version>-<os>-<arch>.exe``, e.g., ``protoc-3.6.1-linux-x86_64.exe``.
+
+Note that artifacts for linux/macos also have the `.exe` suffix but they are
+not windows binaries.
+
+## System requirement
+Install [Apache Maven](http://maven.apache.org/) if you don't have it.
+
+The scripts only work under Unix-like environments, e.g., Linux, MacOSX, and
+Cygwin or MinGW for Windows. Please see ``README.md`` of the Protobuf project
+for how to set up the build environment.
+
+## Tested build environments
+We have successfully built artifacts on the following environments:
+- Linux x86_32 and x86_64:
+  - Centos 6.9 (within Docker 1.6.1)
+  - Ubuntu 14.04.5 64-bit
+- Linux aarch_64: Cross compiled with `g++-aarch64-linux-gnu` on Ubuntu 14.04.5 64-bit
+- Mac OS X x86_32 and x86_64: Mac OS X 10.9.5