Blosxom is a lightweight, open source weblog system, written in only 444 lines of Perl, with minimal requirements. All it requires is that you have permission to run CGI scripts. No SQL database is required. I had intended to use WordPress but SDF requires me to pay for SQL access, and since I would only be using it for my weblog, it did not seem worthwhile.
Blosxom is fully customizable and has a plugin interface. It supports RSS feeds and permanent links. The best part is that entries are simple plain text and HTML files. The script reads the timestamp of each file in order to determine the post date and it reads the directory structure in order to assign categories to each post.