The GNOME project is made up of many components. This page lists all the components, despite apps, that are maintained as part of GNOME Core or GNOME Circle. This in includes libraries, language bindings, static assets, and many more.
The GNOME Core components are developed as part of the GNOME projects. They include the GNOME Shell as well as many libraries, tools, and other projects that are needed for the shell and apps to work.
The GNOME Circle components extend the GNOME ecosystem. GNOME Circle champions the great additional software that is available for the GNOME platform.