Finnix has had PowerPC support for over 5 years now, and is frequently mentioned by PowerPC Linux enthusiasts. Part of the reason is while PowerPC is well supported in the Linux kernel, sadly very few distributions support PowerPC any more. Finnix is one of only two PowerPC LiveCDs, and IMHO the most popular (the other is GeeXboX, a graphical multimedia LiveCD). As for installable distributions, very few support more architectures than 32/64-bit x86 these days.
So I decided to make a list of Linux distributions with PowerPC support. I took the list at DistroWatch.com and weeded out errors, distros that are no longer active, distros that are active but no longer have PowerPC support, etc.
- Finnix, obviously (utility LiveCD)
- CRUX PPC, an independent port of CRUX (barebones distro)
- Debian (desktop/server distro)
- Frugalware (desktop distro)
- GeeXboX (multimedia LiveCD)
- Gentoo (source distro)
- Red Hat Enterprise Linux (server/workstation distro, PPC server edition only, paid)
- Source Mage (source distro)
- T2 SDE (devel distro)
- Ubuntu (desktop/server distro, PPC community support only, latest version not available at this time)
- Yellow Dog Linux (desktop/server distro)
Vine Linux (a Japanese language distro) was on this list when I compiled it a few weeks ago. But since then Vine 6.0 was released with no PowerPC support, and the release notes make no mention of its removal.