hdr software?

I ran across this thread while searching for hdr freeware/shareware.

I'm interested in learning/experimenting with hdr, right now I shoot in raw and use Canon's included software for processing. I've noticed that I can get about 4ev of additional range, 2ev on shadows and 2ev on highlights.

I understand that I should be able to process one raw file to produce the equivalent of bracketed shots, that is, make 3 tiff files at -2, 0 and +2ev, and then merge those in hdr software.

Any recommendations on software?

Thanks!