Six Apart has finally transitioned its Movable Type blogging software to an open-source license, or GPL version 2 to be exact. This is probably due in part to pressure from the success of WordPress, its increasingly popular open-source rival.

Indeed, WordPress is now used on many popular sites, such as TechCrunch and even TechRepublic.

The open-sourced version of Movable Type is called “Movable Type Open Source” or MTOS for short.

According to its FAQ:

MTOS is our abbreviation for the open-source version of Movable Type. It’s a full-featured version of Movable Type, which you can download, use, modify, share, and explore completely free of charge.

The revenue model of paid, commercial support is similar to what RedHat and MySQL AB are practicing:

MTOS will be community-supported, while paying users will always have exclusive access to our professional support team. In addition, commercial add-ons such at MTES and MTCS are only available for paid commercial licensees.

Six Apart has promised to increase the benefits for paid users in the future, although nothing has been announced yet. They can probably expect exclusive add-ons or feature packs.

You can download the latest version of MTOS here.