Blogs
WordPress
WordPress is a state-of-the-art semantic personal publishing platform with a focus on aesthetics, web standards, and usability`. WordPress is both free and priceless at the same time.
FeedONFeed
FEED ON FEEDS, your server side personal RSS (and Atom!) aggregator.
b2evolution
b2evolution is probably the most comprehensive blog engine you can find! It includes almost any feature you could expect from a blog tool, and more!