Owen Winkler has a nice matrix of weblog platforms with requirements, capabilities, cost and more at his own WordPress-driven blog — asymptomatic.
This can be a tricky area to track as there are many views on “blogging” and what other apps can be included in this sphere. I tend to agree with Winkler on a few of his points and not on others.
Instead of starting a battle of semantics over blogging and open source in this post – I will just say that from a pure blogging perspective, he tracked the right software in his breakdown (server installed packages only, not a broad web site CMS (i.e. drupal, mambo and so on) but for personal CMS).
He did not include community-oriented CMS packages like Post-Nuke for the same reasons – those are more site-wide content programs that also drive file management and non-personal weblog functions.
I would encourage folks to review the matrix and submit updates.