The Cinnamon project was formed as a reimplementation of GNOME 2 using the components of GNOME 3. Eventually, it diverged enough to be a true fork, and today the Cinnamon desktop uses GTK3 libraries and forked versions of key GNOME 3 applications to create a “classic” GNOME experience. One of the components contributing to the traditional GNOME experience is Nemo, a file manager based on the GNOME 2 version of Nautilus.

Source: LXer – Why you should try the Nemo file manager on Linux