Whats the difference between stable and developer ATLAS releases?
The vast majority of ATLAS users should download and use only the stable version of ATLAS. Stable versions of ATLAS are released roughly once a year. The most current stable release has an associated errata file, which details all errors found in the release. Stable releases are very well tested, and are much more heavily supported. Developer releases, on the other hand, are meant to be used, as the name suggests, by ATLAS developers, contributers, and people happy to live on the bleeding edge. Developer releases are meant to allow access to the newest ATLAS sources, and may represent a simple snapshot of the internal developer tree. As such, they are essentially untested, and may not build, much less run, correctly. So, while they may possess features not available in the current ATLAS release, only the most experienced of users should consider utilizing them. Developer releases are available from the developer site, while stable releases are available from the ATLAS main page. Stable