The current official Vanilla release, in available packages for Win32 (zip) and Unix (tgz) systems:
Version 0.6.2, 2004-11-10: zip | tgz - vanilla-0.6.2-release-notes
For historical purposes, older Vanilla distributions are also available:
Version 0.6.1, 2004-02-14: zip | tgz - vanilla-0.6.1-release-notes
Version 0.6.0, 2003-12-24: zip | tgz - vanilla-0.6-release-notes
VanillaSBX, which is based on Vanilla 0.5, is also available (for win32 only). Please note that 0.5 is a rather old version, so you won't get the latest, niftiest features. But for quickly taking a test ride into the world of Wikis (Vanilla-style), SBX should do fine.