List of operating systems for Alpha
Active Linux distributions
These are the distributions that still list Alpha as a supported architecture. This is not a complete list.
|Gentoo Linux||Supported as of 10 Nov 2014.|
"The Alpha port is no longer officially supported in the Debian stable release. The last release with official Alpha support was Debian 5.0 "lenny". 
However, the online package files for this release are still hosted online. If you try to download the Alpha port from the normal Debian mirrors, you will not find it. To download it go to the Debian Archive site.
Debian packages can still be downloaded and installed from within apt-get by adding the following to /etc/apt/sources.list:
deb http://archive.debian.org/debian lenny main contrib non-free deb-src http://archive.debian.org/debian lenny main contrib non-free deb http://archive.debian.org/debian-security lenny/updates main contrib non-free deb-src http://archive.debian.org/debian-security lenny/updates main contrib non-free
Also install the signing keys:
apt-get install debian-archive-keyring
An example of a package directory is: http://archive.debian.org/debian/pool/main/l/lxdoom/
Discontinued Linux distributions
This list is incomplete and needs expanding.
|Debian||Not supported. Last supported version was 5.0. However, the online package files are still hosted by Debian.|
Non-Linux operating systems
This list is incomplete and needs expanding. The "Currently maintained" column refers to when the author last checked.
|Name||Currently maintained||Most recent release|
|NetBSD||Yes||Version 6.1.5. Released on 22 Sep 2014.|
|OpenBSD||Yes||Version 5.6. Released on 1 Nov 2014.|
|Tru64 (formerly Digital UNIX)||No||End of standard support was 31 Dec 2012. |
|UNICOS/mk (Cray supercomputers)||Unknown||Note: Mentioned for interest because the Alpha architecture was used in the Cray T3E supercomputer.|
|Windows NT 4.0||No|
|Windows 2000 RC?||No||A release candidate for Windows 2000 on Alpha was distributed shortly before Microsoft ceased development on Alpha.|