Currently The Performa 575 cannot really do anything with Linux for 68k because of the absence of a FPU (FPU emulation isn't running yet). You may, however, be able to run a version of BSD on your Performa (FreeBSD, OpenBSD, or NetBSD). I am currently running the 68k version of NetBSD on my Macintosh IIci - and it's a very mature and complete operating system. I haven't played with any of the others, but I have heard good things about both FreeBSD and OpenBSD.
------------------
Eliott Wolfe
Winnetka, Calif