Hi,
of course, there are free development tools! On the one hand, you can get a somewhat limited version of the CodeWarrior Studio from Freescale that is an all-in-one solution. I have no experience with that, though. On the other hand, you can use the gcc toolchain under both unix and windows with all the tools known from regular gcc development.
For debugging, in case you use gcc, the best choice might be to use a "BDM wiggler", for which several clones can be found as schematic on the web. Then you have full gdb support and do not have to worry much, although it is quite slow concerning transfer speed.
For Codewarrior, you can use Daniel´s TBLCF USB tool, which is quite convenient and a bit faster, but there is currently no gdb support.
HTH,
Wolfgang
(I started with TBLCF, but because of the gdb problems I was not able to solve completely, I switched to PEEDI now and am very confident with this solution, however it is rather costly. There are some other people working on gdb support for TBLCF, too, but I am not up to date about what state it is in right now.)