The largest self-hosted blogging tool in the world, used on hundreds of thousands of sites and seen by tens of millions of people every day.
WordPress is a state-of-the-art publishing platform with a focus on aesthetics, web standards, and usability. WordPress is both free and priceless at the same time. More simply, WordPress is what you use when you want to work a workable blogging software solution.
To run WordPress your host just needs a couple of things:

• PHP version 4.3 or greater
• MySQL version 4.0 or greater