$ wget https://github.com/protocolbuffers/protobuf/releases/download/v2.5.0/protobuf-2.5.0.tar.gz
$ tar zxvf protobuf-2.5.0.tar.gz
$ cd protobuf-2.5.0
$ ./configure
$ make
$ make check
$ make install
$ protoc --version
$ wget https://github.com/protocolbuffers/protobuf/releases/download/v2.5.0/protobuf-2.5.0.tar.gz
$ tar zxvf protobuf-2.5.0.tar.gz
$ cd protobuf-2.5.0
$ ./configure
$ make
$ make check
$ make install
$ protoc --version