iHaiDeeZ / xemu-ps4

xemu (original Xbox emulator) ported to jailbroken PS4: Vulkan on RADV/GNM, PS4 frontend. Paused: boots Halo 2 to its title screen at ~1 fps.

libretro / RetroArch

Cross-platform, sophisticated frontend for the libretro API. Licensed GPLv3.

webui-dev / webui

Use any web browser or WebView as GUI, with your preferred language in the backend and modern web technologies in the frontend, all in a lightweight portable library.

OpenVPN / openvpn-gui

OpenVPN GUI is a graphical frontend for OpenVPN running on Windows (10 and 11). It creates an icon in the notification area from which you can control OpenVPN to start/stop your VPN tunnels, view the log and do other useful things.

celluloid-player / celluloid

A simple GTK+ frontend for mpv

tarwin / tinyjsapp

Build native apps in JS. Backend, frontend. ~5Mb.

llnl / rose

ROSE is an open-source compiler framework engineered by LLNL supporting program analysis and transformation at both the source and binary levels. ROSE can act as a compiler frontend for C, C++ (including applications which use UPC, OpenMP, or Cuda), Fortran, Java, Ada, and supports ELF and PE binary formats for a variety of instruction sets.