The Midgard Community
Linux, Unix and Mac OS X
PHP (Midgard framework)
Content Management Framework
Midgard is a free software community aiming to build content repositories useful for synchronized desktop, mobile and web applications. Since 1999, the project has been releasing both the content repository library itself, and also many useful tools around it, like web frameworks for PHP and Python.
The community is fully volunteer-driven, with individuals and multiple companies working together to build useful common infrastructure.