MATE Desktop
caution
The MATE Edition is deprecated. XFCE has been included to replace it. See the Solus 4.4 blog post here
MATE Desktop is provided by the MATE Edition of Solus. They describe it as:
The MATE Desktop Environment is the continuation of GNOME 2. It provides an intuitive and attractive desktop environment using traditional metaphors for Linux and other Unix-like operating systems.
Here are some links related to this project that you may find helpful: