IBM has been a major Linux supporter for years. And, with the arrival of UnitedLinux, both IBM's internal programming efforts and its independent software vendor (ISV) partners will have much less trouble and spend less money porting and building Linux applications. Given all this, it should come as no surprise that of the more than 300 IBM middleware products available, more than 50 are now available on Linux on IBM's Intel-based xSeries servers and 20 are ready to go on the mainframe zSeries. IBM's WebSphere, its Java 2 Enterprise Edition (J2EE) application server and leading middleware product, has long been available on Linux for the X and Z series, and is in late beta on the iSeries (formerly the AS/400 line) and the pSeries (also known as the RS/6000 line). WebSphere on these platforms is expected to be available in the first quarter of 2003, with the iSeries version appearing first. Other core IBM middleware products -- its DB2 database offering, Domino, and the MQSeries -- are also already available on the X and Z lines. Simultaneously, IBM ISV partners -- such as AccPac, Computer Associates, Sage, SAP, and SAS -- either have brought their business applications and middleware products to IBM's Linux lines or are in the process of doing so. Why are they bringing their middleware to all these different platforms? The simple answer is that different customers have different needs. Adam Jollans, IBM's Linux strategy manager, says a small shop or a decentralized company might go with the xSeries, whereas a larger company that's comfortable with centralized computing might go with the midrange iSeries or mainframe zSeries. The one platform that isn't getting much attention is the pSeries. While acknowledging that most RS/6000 administrators are happy with the more mature AIX 5L, Jollans says IBM plans to bring its middleware offerings to Linux on this platform as well. He foresees a day when Linux-only shops will want to move to the eight-way processing power of the pSeries, and they'll want to take their Linux middleware-based applications with them. Jollans says customers want enterprise middleware on Linux for workload consolidation, server consolidation, and Web applications. "Two to three years ago, it was technical people wanting Linux for file and Web servers," he says. "Now it's IT managers and CIOs looking for a good, stable operating system and middleware." Cost is another consideration. "Time and time again our customers are looking at Linux as a way to save money," Jollans says. "Rarely do other options come to play." Ed Lynch, IBM's Linux systems manager, says another long-term driver is making IT departments look to Linux middleware. "What keeps CIOs up at night? 'I've got too much work to do and not enough bodies to do it.' So where are people with skills and what skills do they have? There's a natural wave to ride on and that's Linux," he says. Another reason, according to Dan Kusnetzky, IDC vice president for system software research, is that IBM sees Linux as an emerging market. With little additional effort, he says, IBM can move its AIX efforts to Linux while supporting Linux unification. "With this, IBM can ride Linux into new markets and into places where IBM hasn't been able to get into for years." Kusnetzky considers this Linux strategy a wise move because for IBM, "the more platforms it can play on, the more revenue it can attain." Exactly how much revenue IBM gets from Linux middleware (and Linux in general) is almost impossible to determine. IBM refuses to reveal exact revenues generated from its famous billion-dollar investment in Linux and AIX. Kusnetzky believes that AIX drives most of the revenue, but that in two to three years, Linux and its middleware will be IBM's most profitable line.