If you need or want to develop business software, like Gnome technology and desktop, and don’t want to reinvent the wheel, you should have a look to this project developed by us at Igalia:
From the project webpage: Fisterra is an open source GNOME development framework. It is indicated for the implementation of whole business management applications, ad hoc ERPs or modules of other management systems.
The main features of the project can be found here.
All the code is under GPL license. In the webpage there is a lot of information on how to collaborate in the project.