Chamilo comes in two flavours, the 1.* (or "classic") series and the 2.* series.
Chamilo 1.9.4 - Puebla
Release name: Puebla
Prerequisites: PHP>=5.3, MySQL/MariaDB>=5.1
Release date: 18/01/2013
Chamilo is free software. Its development process is public.
Feel free to contribute on http://support.chamilo.org/
If you're a developer and you want to checkout the "live" source, check http://code.google.com/p/chamilo
Chamilo 3 - Bradypodion
Version: 3 - Download it here
Release name: Bradypodion
Release summary: A simple upgrade from Aldrin to Bradypodion is not possible, because of serious refactoring of the core in the latest version. More information and documentation on http://lcms.chamilo.org or via http://www.chamilo.org.
Release date: 30/04/2013