Version 1.5.1 is the latest release, and was made available Februrary 2013.
Check out Getting Started if you are looking to set up Obsidian.
Our FAQ is also worth checking out if you have questions about Obsidian or want more context about what it does.
The User Guide will provide all the information you need to use all of Obsidian's features.
Full Administration Capabilities
Obsidian features a rich administration web interface, allowing easy monitoring and management. See the Admin Web Application Guide for details.