Google protobuf in Linux

Also, if you are in fact on Ubuntu, then you can also fetch the source package from Debian unstable and rebuild them locally if you want packages that are more current than the last cutoff (which for Ubuntu 9.10 was some time late last summer). That way you end up with .deb packages and you preserve a normal upgrade path (rather than littering /usr/local with one-off installs).

First, you need to compile you source code from protobuff (in the root folder):

./configure  
make   
make check   
make install

Second:

echo "/usr/local/lib">>/etc/ld.so.conf  
echo "/usr/lib">>/etc/ld.so.conf    
ldconfig

Third:

export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig:$PKG_CONFIG_PATH

Read README.txt in root folder for more info.

It's probably installed into /usr/local/bin

On Ubuntu at least, you can apt-get install protobuf-compiler instead.

From the INSTALL.txt:

Installation Names

By default, 'make install' will install the package's files in '/usr/local/bin', '/usr/local/man', etc. You can specify an installation prefix other than '/usr/local' by giving 'configure' the option '--prefix=PATH'.