Moodle

Moodle is a course management system (CMS) - a free, Open Source software package designed using sound pedagogical principles, to help educators create effective online learning communities. You can download and use it on any computer you have handy (including webhosts), yet it can scale from a single-teacher site to a 50,000-student University.
Moodle is a free software e-learning platform (also known as a Course Management System (CMS), or Learning Management Systems (LMS), or Virtual Learning Environment (VLE)).

Moodle features

Moodle has many features expected from an e-learning platform including:

Forums
Content managing (resources)
Quizzes with different kinds of questions
Blogs
Wikis
Database activities
Surveys
Chat
Glossaries
Peer assessment

Multi-language support (over 60 languages are supported for the interface)
Moodle is modular in construction and can readily be extended by creating plugins for specific new functionality. Moodle's infrastructure supports many types of plugin:

Activities
Resource types
Question types
Data field types (for the database activity)
Graphical themes
Authentication methods
Enrolment methods
Content Filters
Many third-party Moodle plugins are freely available making use of this infrastructure.

PHP can be used to author and contribute new modules. Moodle's development has been assisted by the work of open source programmers. This has contributed towards its rapid development and rapid bug fixes.

Specification

Moodle runs without modification on Unix, Linux, FreeBSD, Windows, Mac OS X, NetWare and any other systems that support PHP, including most webhost providers.
Data is stored in a single database: MySQL and PostgreSQL were the only feasible options in Moodle 1.6. Version 1.7 released November 2006, and makes full use of database abstraction so that other databases can be used just as easily (Oracle and Microsoft SQL Server are two specific target DBMSes). The current version of Moodle, version 1.8, was released in March 2007 with improved roles management.

Interoperability
There are many dimensions to interoperability for e-learning systems. Moodle's interoperability features include:

*Authentication, using LDAP, Shibboleth, or various other standard methods (e.g. IMAP) *Enrollment, using IMS Enterprise among other standard methods, or by direct interaction with an external database
*Quizzes and quiz questions, allowing import/export in a number of formats: GIFT (moodle's own format), IMS QTI, XML and XHTML (NB although export works very well, import is currently not complete)
*Resources, using IMS Content Packaging, SCORM, AICC, LAMS Integration with other Content Management Systems such as Postnuke (via third-party extensions)
*Syndication using RSS or Atom newsfeeds - external newsfeeds can be displayed in a course, and forums, blogs, and other features can be made available to others as newsfeeds.
*Moodle also has import features for use with other specific systems, such as importing quizzes or entire courses from Blackboard or WebCT.