Qt5 Alpha released

I don't know where you got the idea that XCB refuses to implement GLX. XCB just needs a couple of technical enhancements so that it can handle the GLX protocol. In particular, the libraries built on top of GLX need the ability to process a GLX-related event invisibly without it reaching the application's event loop (because the application won't know what to do with it, and compatibility with the GL and GLX APIs requires that the application not have to know what to do with it). XCB currently doesn't support a side-channel event like that, but as of recently, we have a plan to fix it.