ATutor

ATutor is one of the FOSS software recomendation for education purpose. If you haven't met ATutor before, here is the small description from their official website:

What is ATutor?
ATutor is an Open Source Web-based Learning Content Management System (LCMS) designed with accessibility and adaptability in mind. Administrators can install or update ATutor in minutes, and develop custom templates to give ATutor a new look. Educators can quickly assemble, package, and redistribute Web-based instructional content, easily retrieve and import prepackaged content, and conduct their courses online. Students learn in an adaptive learning environment.

Why ATutor?
ATutor is the first fully inclusive LCMS, complying with the W3C WCAG 1.0 accessibility specifications at the AA+ level, allowing access to all potential learners, instructors, and administrators, including those with disabilities who may be accessing the system using assistive technologies. Conformance with W3C XHTML 1.0 specifications ensures that ATutor is presented consistently in any standards compliant technology.

ATutor has also adopted the IMS/SCORM Content Packaging specifications, allowing content developers to create reusable content that can be swapped between different e-learning systems. Content created in other IMS or SCORM comformant systems can be imported into ATutor, and visa versa.

They have added new features in their latest version (1.4.3). See the Changelog for details