A fair number of people use Blosxom, Rael Dornfest's weblog software, for its simplicity and power, and given Movable Type's recent change to its pricing structure, even more people may do so soon.
The major drawback, IMHO, has to do with comments, or "writebacks," which must be written with HTML tags, cannot be previewed before being posted, and can't be edited once posted. I searched for quite some time in vain for a plugin that would at least allow a preview, which would mitigate the problem substantially.
Finally I gave up and dug around until I found a JavaScript that could be modified to produce at least a crude preview functionality. WARNING: I am not an especially competent or elegant programmer, so the following will almost certainly offend sensitive readers! The essence of the hack is to replace the foot.writeback file that comes with the vanilla installation. I created a replacement HTML file, which permits both a preview window and a mini-primer for those posters not familiar with HTML tags. Try one of these two links to view the source; the .txt file will actually be interpreted by Safari for some reason ...
.src text file text file
I am, of course, open to other, better solutions -- as I said, this is just something I cobbled together in order to provide a quick fix. It's not a plugin, and it's hardly elegant. But it does have the advantage that it works.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20040527154619100