The alliance between IBM and Sun drew a rather short but succinct response from HP: Welcome to the party.

While IBM is getting into the game to sell Solaris on its x86 hardware, HP has been selling x86 servers for running Solaris for more than a decade. And it has enjoyed a decent business in the process.

Sun has offered Solaris on x86 since version 2.1 shipped in 1992, but its support has been sporadic, and it always played second fiddle to the SPARC version.

It wasn't until Solaris 10 in 2005 that Solaris for x86 truly made parity with the SPARC version, and HP has been getting as much mileage out of it as possible. So far, it says it has racked up $1 billion in x86 hardware sales to run Solaris.

"We've been pretty bullish about it," Paul Miller, vice president for enterprise storage and servers marketing at HP told internetnews.com. "It's been a good business for HP. If you look at the IDC numbers, we can claim more people run Solaris on ProLiants than any other x86 out there."

HP uses emulation technology from Transitive, the emulation firm that also provides the translation engine used in Apple's Rosetta software to run Macintosh PowerPC applications on Intel-based Macintoshes. Native SPARC applications will run on x86 with no modification required.

"We've taken 16-CPU SPARC servers that are five years old and put the apps on a four-socket Xeon or Opteron, and the customers have more headroom than they know what to do with," Miller said.

He added that the HP appeal is lower cost systems and a much greater variety than Sun offers. Its x86 offerings are very new. Sun has only had Opteron-based servers on the market for 18 months and just recently struck a deal with Intel, but the Xeon-based servers are not on the market yet.

"If you look at their portfolio versus ours, they've got a very immature blade offering," said Miller. "We have multiple different Xeon and Opteron and Itanium blades with full management support. We offer 15 different platforms in x86, from SMB towers to four-socket AMD servers."

Miller said he sees the trend moving away from old Unix servers to Linux, including HP's own HP-UX, as much as Solaris. "The inevitable path is to Linux. IDC data says the only operating systems growing are Windows and Linux. How fast they transition is the question. These are multi-year transitions," he said.

But Jean Bozman, vice president with IDC, disagrees. "True, Linux is growing, but the Unix market is not going away anytime soon," she told internetnews.com. "We see the Unix market to be fairly strong through this year. From what we can see the Unix server market is going to be around a long time."

Bozman sees the IBM deal as a chance for Sun to increase its software revenue, which CEO Jonathan Schwartz would like to see grow. "This is not about hardware. This is about growing Sun's software business and software revenue, and there's so much x86 out there Jonathan thinks there's plenty of upside."

Miller said HP plans to stay the course that has worked for the company. "We're going to continue to support Solaris the way we have," he said.