RetroArch - RetroArch is a frontend for emulators, game engines and media players.
Materia - Materia is a development environment to build advanced mobile and web applications.
Batocera.linux - Batocera.linux is an open-source and completely free retro-gaming distribution that can be copied to a USB stick or an SD card with the aim of turning any computer/nano computer into a gaming console during a game or permanently.
adapta-gtk-theme - An adaptive Gtk+ theme based on Material Design Guidelines - adapta-project/adapta-gtk-theme
Playnite - Source code generated using layoutit.com
Zukitwo - Zukitwo is a Gnome Shell and GTK theme that currently works on Gnome Shell 3.14 and the latest version of GTK.