itch.io - An online game marketplace and community.
Materia - Materia is a development environment to build advanced mobile and web applications.
GOG.com - DRM-free game store, selling both new and old titles. No clients required.
adapta-gtk-theme - An adaptive Gtk+ theme based on Material Design Guidelines - adapta-project/adapta-gtk-theme
GnuPlot - Gnuplot is a portable command-line driven interactive data and function plotting utility.
Zukitwo - Zukitwo is a Gnome Shell and GTK theme that currently works on Gnome Shell 3.14 and the latest version of GTK.