Textpattern is an open source CMS based on the use of MySQL and PHP mainly used for creating blogs, if you know a bit ‘in depth can also be exploited for the construction of complex sites such as portals or corporate sites.

Textpattern, TXP abbreviated, it can also be integrated with plug-ins written by the community of people that use it.

For content management, native TXP relies on Textile, a Humane Web Text Generator as defined by its creator, or a text editor humanized. The combination of TXP Textile and allows the creation of websites and accessible XHTML.

SOURCE: http://it.wikipedia.org/wiki/Textpattern