Blaž Tomažič has expressed interest (mailing list message) in creating a Glide state tracker for Gallium3D so that any ancient applications still relying upon this once proprietary graphics API intended for 3Dfx Voodoo hardware can seamlessly run with a modern open-source Linux graphics stack. But there is barely any major software around that still uses Glide, let alone Linux software.
In theory it would be easy to write such a state tracker since the Glide API is much simpler than the OpenGL specification, even of OpenGL from twelve years ago, but at the same time Gallium3D and its drivers are designed around modern shader-based graphics processors and not the hardware that Glide was designed around in the first place.
There are a number of Glide/Voodoo emulators already out there, including wrappers for translating Glide's API to OpenGL. With a Glide state tracker, however, it would be native execution on the graphics processor. This state tracker would live alongside the OpenGL (Mesa), OpenGL ES, OpenVG, Python, and X.Org/EXA/XvMC state trackers already in existence for this Mesa-based driver architecture.
This proposed state tracker, however, has already been largely shot down by Brian Paul in this message. Hopefully another interesting Gallium3D-focused project will materialize and of something that's of use to the greater Linux desktop community.