while not blog "software", one could say that the contents of an html directory exposed by, for example, http://weirdmachinehostname.university.edu/~username/ were the earliest blogs. Hand crafted HTML homepages and such.

Hmm nah, I remember “blogging” explicitly meant drafting and publishing posts directly from a website form, as opposed to crafting HTML documents and uploading them over FTP (which was what people did at the time and obviously complained about.)

The word "blog" appeared a few months before the infrastructure to draft and publish posts directly from a website form. And the concept of diaries/weblogs that it designated was a few years older.

B2/Cafelog (from where Mike/Matt forked to WordPress) was also 2001.

I dumped MT (due to my Perl-aversion) for B2 and then onto the WordPress fork when B@ founder Valdrighi stopped active development of it.

Whilst not an open blog platform, CmdrTaco of Slashdot claims his Slashdot prototype 'Chips and Dips' which he created in 1997, was one of the first 'blogs'.