- Joe Biden (Democrat) - Linux, Zope by Interlix
- Hillary Clinton (Democrat) - Windows Server 2003, Microsoft-IIS/6.0 by Paul Holcomb
- Christopher Dodd (Democrat) - FreeBSD, Apache by pair Networks
- John Edwards (Democrat) - Linux, Apache by Plus Three
- Mike Gravel (Democrat) - Linux, Apache by Voxel Dot Net, Inc.
- Dennis Kucinich (Democrat) - Linux, Apache by New Age Consulting
- Barack Obama (Democrat) - FreeBSD, Apache by pair Networks
- Bill Richardson (Democrat) - Linux, Zope by Interlix
- Wesley Clark (Democrat) - Linux, Apache by Voxel Dot Net, Inc.
- Al Gore (Democrat) - Linux, Apache by Rackspace
- Sam Brownback (Republican) - Windows Server 2003, Microsoft-IIS/6.0 by RackForce Hosting, Inc.
- Jim Gilmore (Republican) - Linux, Apache by 1&1 Internet, Inc.
- Rudy Giuliani (Republican) - Linux, Apache by RackSpace
- Mike Huckabee (Republican) - Windows Server 2003, Microsoft-IIS/6.0 by LNH Inc.
- Duncun Hunter (Republican) - Windows Server 2003, Microsoft-IIS/6.0 by Individual
- John McCain (Republican) - Windows Server 2003, Microsoft-IIS/6.0 by Smartech Corporation
- Ron Paul (Republican) - Linux, Apache by Rackspace
- Mitt Romney (Republican) - Linux, Apache by Rackspace
- Tom Tancredo (Republican) - Windows Server 2003, Microsoft-IIS/6.0 by Interland
- Fred Thompson (Republican) - Windows Server 2003, Microsoft-IIS/6.0 by LNH Inc.
- Tommy Thompson (Republican) - Windows Server 2003, Microsoft-IIS/6.0 by Time Warner Telecom, Inc.
- Chuck Hagel (Republican) - Windows Server 2003, Microsoft-IIS/6.0 by Individual
- Newt Gingrich (Republican) - Windows Server 2003, Microsoft-IIS/6.0 by Smartech Corporation
