Excellent Weblogging Article Published in March 2003 Edition of Linux Journal
Doc Searls and Dave Sifry wrote an excellent article in the March 2003 issue of Linux Journal called Building with Blogs. If you want to read the article today, you'll have to buy the magazine, because LJ doesn't put most of its content on the web (at least immediately).
The article has a great overview of blogging systems, discussion sites, content management systems, and wikis, as well as a list of 10 criteria that can be used to determine whether the configuration of any one of these software platforms qualifies as a weblog.