The most recent information on 3DFX's web site says that the site will be permanently closed on February 19, 2002. nVidia, who bought all of 3DFX's assets and none of the liabilities (including and especially support for us, 3DFX's customers), has shown no interest whatsoever in providing support or driver updates for Voodoo video cards.
Fortunately, 3DFX Voodoo card owners are not (yet) out in the cold. The Voodoo Files web site has all of the drivers from 3DFX as well as 3rd party drivers including (and especially) Voodoo 4/5 Glide drivers for Windows XP.
During the installation of the 3rd party Voodoo 4/5 drivers for WinXP, there is a "directory error" message. This relates to installing the 3dfx Tools (which fails). It can be ignored. The drivers themselves do install and seem to work properly. You should also ignore the warning that the drivers are not signed by Microsoft and "continue anyway."