At the 1999 LinuxWorld Expo in San Jose, Calif., Linus Torvalds joked about his goal for the operating system he started: “Total world domination.”

Six years later, Linux has won a spot in government workplaces around the globe.

Because Linux can run on older, cheaper hardware, agencies can extend the hardware’s lifecycle. Even with a support contract with Red Hat Inc. or Novell Inc., the acquisition cost of Linux is tiny in contrast to deploying a new version of Windows on existing hardware.

Linux has found a home in scientific applications, and federal researchers have made major contributions to the Linux community. The Energy Department uses both Novell’s SuSE and Red Hat, and the National Oceanic and Atmospheric Administration also uses Red Hat.

NASA does a lot of software development on the LAMP platform, the collection of open-source software that includes Linux, Apache Software Foundation’s Apache Web server, MySQL database, and Perl and Python scripting languages.

Nearly two years ago the Office of Management and Budget made Linux part of its Technical Reference Model for enterprise architectures. Although OMB advised chief information officers to look at potential licensing and security problems with open-source software, many such doubts are fading. SuSE recently won a Common Criteria Evaluation Assurance Level 4 rating — the same level assigned to OSes such as Sun Microsystems Inc.’s Trusted Solaris.

Novell is helping to win more converts by all but eliminating the differences between its proprietary NetWare OS and its SuSE Linux server. This spring, the company plans to unveil Open Enterprise Server, which has all the functionality of its Novell NetWare but on the Linux platform.

S. Michael Gallagher, a Maryland network manager, writes about computer technology.