Mir
Wayland
Y Window System
DirectFB
Xynth Window System
XQuartz
xmodmap
Metisse
SourceForge
GitHub
GitLab
BitBucket
openDesktop.org
Gitea
Launchpad.net
OSOR
Mir
SourceForgeWayland - Wayland is intended as a simpler replacement for X, easier to develop and maintain.
GitHub - Originally founded as a project to simplify sharing code, GitHub has grown into an application used by over a million people to store over two million code repositories, making GitHub the largest code host in the world.
Y Window System - Y Window System is a platform that allows you to improve the speed, working, and efficiency of the application in your operating system and helps you to increase the responsiveness of applications similar to any locally based app.
GitLab - Create, review and deploy code together with GitLab open source git repo management software | GitLab
DirectFB - DirectFB is a web-based platform that provides you with complete access to a software library that you can use for the acceleration of graphics, handling the input devices, and others for your Linux operating systems.
BitBucket - Bitbucket is a free code hosting site for Mercurial and Git. Manage your development with a hosted wiki, issue tracker and source code.