This FAQ documents the 2.0 and 2.2 series of kernels. If you are currently using a 0.x or 1.2 series kernel, I recommend that you read the Linux/m68k 2.0 announcement (and all the documents it says to read) and then upgrade to a 2.0 kernel. The 0.x and 1.2 series of kernels are obsolete and completely unsupported.
Most things said about 2.0 kernels apply also to the 2.1 development series and 2.2 semi-stable kernels, unless otherwise noted. I recommend against trying to use the 2.1 and 2.2 kernels until you are accustomed to using Linux, or you need to use hardware that's not supported in a 2.0 kernel.
The latest versions of the kernel and boot loaders, as of this FAQ release:
Mainstream Linux kernel (released by Linus; current information at http://www.cs.Helsinki.FI/cgi-bin/linuxversion):
Previous Stable: 2.0.38
Current Stable: 2.2.12
Linux/m68k kernel (released by Jes):
Previous Stable: 2.0.36
Amiboot (AmigaOS bootstrap): 5.6
Ataboot (Atari bootstrap): 3.1
Penguin (Mac bootstrap): 17
Amiga LILO (low-level Amiga bootstrap): 2.2
MVME LILO (low-level VMEbus bootstrap): 1.0
For current versions of other software, please refer to the Changes document included in the kernel sources (also available at http://www.linuxhq.com/).