The move illustrates the upheaval that Linux, a Unix-like operating system, is causing as it grows from a hobbyists' project to a force that major server makers are reckoning with.
Sun, IBM, Hewlett-Packard, Compaq Computer, and SGI all have their own server products based on their own chips with their own variety of Unix, but all are acting to make sure the wave of Linux popularity doesn't leave them behind.
The software that Sun released today, an enhancement to a program called lxrun, intercepts program commands to the Linux operating system and translates them, where necessary, into Solaris, said Patrick Dorsey, product line manager for Solaris marketing at Sun. Sun programmers wrote the addition and contributed it back to the open-source community, he said.
Sun believes the software will help its own systems as well, though. "When Linux gains, we believe Sun wins. When Solaris wins, Sun wins, obviously. Compatibility helps both Solaris and Linux win in the market, as opposed to, say, Windows NT," Dorsey said.
The software helps Linux as well, because Linux programmers essentially will be able to distribute products to more customers, Dorsey said. "Applications written for Linux now have a larger market opportunity," he said.
So far the software works only on the version of Solaris that runs on Intel-based computers, but in the future, Sun plans to make sure the software works also on Sun's UltraSparc-based computers.
In addition, Sun also announced it would release programming tools in June to make it easier to write software that runs on either Solaris or Linux. The tools will be free, but Sun doesn't plan to release the source code itself, Dorsey said.
The developer tools will make it easier for programmers to maintain a single body of source code that can be compiled to run on either Solaris or Linux machines, he said.
Sun also is helping the UltraPenguin effort in the Czech Republic to make sure Linux works on UltraSparc computers. Sun donated to the project technical assistance with documentation and knowledge of the hardware architecture, as well as Sun computers to work on, Sun said.
Sun announced its support for Linux in December.
The lxrun program originally was developed by Santa Cruz Operation engineer Michael Davidson, who released the program to the open-source community in 1997. SCO sells Unix that runs on Intel chips, and the company announced that Linux programs would run on UnixWare in February.
Analysts as well as SCO competitors believe the company will be hurt by Linux, but SCO believes Linux is helping the company by convincing people that Unix on Intel is a viable alternative to Windows NT.
Meanwhile, Sun, which sells its Solaris version of Unix for both Intel and UltraSparc systems, also says it's not worried that Linux competes with its own Unix products. "I don't see a lot of overlap at this point. Linux is playing to a different, lower-end market than Solaris is," Dorsey said.
The lxrun additions aren't an effort to get Linux users to switch to Solaris, Dorsey added. "We're not trying to get people to migrate. Look at the number of applications on Solaris. We're not really hurting."
Instead, he said, "We're trying to make a contribution to the open-source community and spur innovation around open computing and open platforms," he said.