Aegir is a completely new iteration of the original Hostmaster project written by Adrian Rossouw. The original version has been running the hosted service provided at http://bryght.com for nearly 4 years, hosting literally thousands of sites, and has been implemented for several large clients. Originally, the system would only manage a single Drupal instance, on a single web server with a single database server, and as the requirements grew (concurrently running multiple versions of Drupal and then needing to manage several servers), it grew considerably in (unplanned) complexity.
There were also non-ideal implementation and licensing issues, such as the choice of Python and PostgreSQL for the backend and not developing the system as an "invite-only" GPL project, which severely limited the number of developers that were attracted to the project. Because of the system requirements, it was also very difficult for new users to install, and had many unnecessary points of failure.
The Aegir hosting system has been designed with all these issues in mind, and the lessons learned have formed the basis of many of the Aegir Project Goals. The code was committed to Drupal.org in november 2007 and has seen multiple production-ready but still "alpha" releases there in the two following years.
- 0.1 marked the first Drupal 5 and "multi-site" capable version.
- 0.2 marked the first multi-platform version, which supported upgrades between different Drupal versions
- 0.3 marked the port of the frontend to Drupal 6
Then in 2009, a major overhaul of the code was performed to provide "multi-server" support, which led to numerous 0.4-alpha releases (about 20) and, around the end of 2009, required the move to git as a version control system even though Drupal.org was still stuck in CVS-land, which meant Koumbit.org started hosting the git repositories on their servers.
Aegir now exceeds the capabilities of the original HostMaster system and is in use by numerous real world projects.
On January 8, 2014 the 2.0 release ships with significant stability improvements, Drush 5 and 6 support, subdirectory multisite support, improved nginx support, native views and much, much more.