Glom is in GNOME's cvs. To check out the latest version:
cvs -d :pserver:firstname.lastname@example.org:/cvs/gnome login (hit return as the password) cvs -z3 -d :pserver:email@example.com:/cvs/gnome co glom
It is also in jhbuild, which might make things easier for you.
See the Build Help page for more details.
Glom is built using gtkmm, the C++ wrapper for GTK+. It uses the Document/View model from Bakery, and the libxml++ C++ XML parser. It uses Python for custom field calculations. PostgreSQL databases are accessed via libgda.