You can download the latest version of globus-build-service here.
Source code
The globus-build-service bundle currently contains
no compiled code (only BASH and Ant files), so the downloadable bundle
is itself a source distribution. However, if you want to access the latest version of the source code, you can do so through CVS.
cvs -d:pserver::/cvsroot/gsbt login
cvs -z3 -d:pserver::/cvsroot/gsbt co -P globus-build-source
You can also browse the source code through SourceForge's CVS Web interface: