WordPress started out as a little bit of code and has progressed to a comprehensive system of typography for daily entries. Since then it has developed into the biggest tool for bloggers worldwide, used in hundreds and thousands of places and seen by millions of people every day. Wordpress is an open source software. It groups together a bigger team than on most commercial platforms. It can be used for whatever you like, from your own simple home page to an intranet site for the largest of international companies - and all this for free!
You benefit from a extensive online administration system that facilitates the uploading and management of your blog. The administration is extremely comprehensive but remains very simple at the same time.
To be able to use wordpress, you need to have a php or mysql host provider (php host provider, mysql host provider)
Wordpress is available for free: wordpress
If you want to create a wordpress blog, wordpress.com offers a free service which can be found on its website.
The system's only drawback is for french speakers because unlike dotclear, most of the references on wordpress are in English.