Gambit has SRFIs 0, 4, 6, 8, 9, 18, 21, 22, 23, 27, and 39 built-in.
Other SRFI:s have been, or need to be ported.
A number of SRFI's have been ported, (at least, the barebones implementation) and are available at this SVN repository: http://bunny.jonnay.net/zengarden/trunk/lib/srfi-pack/