From SELinux Wiki
Efforts are underway to extend Flask/TE to the X.org system, to provide flexible fine-grained MAC to the desktop.
- XACE is the X Access Control Extension, which provides mediation hooks and an API for plugging in different access control modules.
- XSELinux is the Flask/TE plugin for XACE.
Eamon Walsh presented on the topic at the 2007 SELinux Symposium: