<hr /><i>lrem added on 2011-11-19 13:32:54 UTC:</i><br />
Apart from being somewhat intrusive, usage of FastCGI devkit would require its authors to submit the copyright releases (which, I don't know why, I feel to be unlikely).

While I've always been happy with FastCGI, I don't feel it's actually needed for Fossil. It seems to be efficient enough to use a proxy pass to a standalone Fossil server.