DOOR (Digital Open Object Repository) is a free learning object repository implementing IMS metadata and content package specifications. It's usefull to all organizations producing, storing and reusing digital learning contents.

Ps and Qs: Processing QTI using PHP, a lightweight PHP library for interpreting IMS QTI files. This is a very simple framework which sits on top of PHP's "Expat" XML parser, intended largely as a template for using QTI in PHP applications - but includes a basic test-taking functionality.