Custom build (bsp/vis) tools for Quake have been released. He's looking for feedback on these so be sure to let him know your results, issues, etc. You can get the full details on how to use them on the tools website and you can download them directly from here.
Thanks to func_msgboard for the heads up.
* light and vis both now multithreaded on Unix and Windows platforms
* vis now writes a state file every 5 minutes so it can resume if needed
* qbsp and vis now support a form of detail brushes, similar to Quake 2. See qbsp.txt for further details.
* added a small optimisation to vis for a minor speedup (usually only 1-2%)
* build system re-written and lots of cleanups all over the code