Here you can find wiki pages for GNOME applications. It is not a list of every GNOME application, and not every app in the list is actively developed.
Template can be used as reference on new application pages.
For list of project homepages see Projects.
One way to help the GNOME project is to help with application maintenance.
Applications looking for maintainer:
Applications looking for co-maintainer:
See MaintainersCorner for general information about the maintenance of a GNOME module.
If you have time and interest in maintaining an application - get in touch with the previous maintainers or send an e-mail to the desktop-devel-list.