Users of Microsoft's Java Virtual Machine have an extra three years to drop the software and migrate to Microsoft's .Net or a competing Java product following the company's broad deal with Sun early this month.Microsoft was set to end support for its JVM on Sept. 30, much to the dismay of developers who built applications to work with the software. Now Microsoft has extended security patch support for its JVM until Dec. 31, 2007, Brian Keller, a Microsoft product manager, said Tuesday. Security patches are the only support Microsoft currently provides for the JVM."This is certainly very good for many of our customers. It means they have over three additional years to migrate their applications. In some cases those applications were already set to retire before 2007," Keller said. The extension was agreed on in the settlement and collaboration pact Microsoft recently struck with Sun.A JVM is software that enables users to run applications written in Java, the programming language created by Sun. Many developers have built applications for Microsoft's JVM because the software is widely distributed. Most Windows users have Microsoft's JVM installed, according to Keller.Java applets are widely used to make Web sites, such as banking and shopping sites, more dynamic.After a feud over Microsoft's alleged misuse of Sun's Java technology, the companies agreed in a legal settlement in 2001 that Microsoft would retire its JVM on Jan. 2, 2004. Microsoft and Sun last October agreed to an extension until September 2004 and earlier this month further extended the period in which Microsoft can provide security patches for its JVM until the end of 2007.Microsoft advises customers not to put off moving from its JVM. The software is outdated because Microsoft, under its agreement with Sun, has not been allowed to enhance it but only to provide critical security patches, Keller said.Extending support is good news for users, said John Rymer, a Santa Clara vice president at Forrester Research. "Users faced a forced migration, essentially one that created no value, replacing one JVM with another," he said. Many users aren't interested in migrating to Microsoft's .Net platform but want to stay with Java, he said."There is cost and time involved in the migration. Users have gotten a reprieve as a result of this peace treaty with Sun. However, they still will face migration at some point, Microsoft has been pretty adamant about not supporting Java," Rymer said. Keeping the Microsoft JVM after support expires would be a security risk, he saidGoing forward, Rymer sees two basic scenarios. Customers will have to drop the Microsoft JVM - "2007 is a pretty relaxed schedule," he said - or Microsoft will reach a new licensing agreement for Java with Sun."I don't think it is an immediate possibility, but depending on how they get along and how their businesses coincide, we may see Microsoft license Java from Sun again," Rymer said.Microsoft has set up a Web site to advise customers of their options, which includes migrating to the Microsoft .Net framework or to a different JVM. Microsoft provides tools, such as its Visual J# .Net, to help developers migrate their Java applets and applications to its .Net framework, Keller said.Keller couldn't say if Microsoft, as a result of its newfound friendship with Sun, would take out a new Java license from the Santa Clara company in the future. "At this point our technology investment is the .Net framework. I am not aware of any decisions to relicense Java," Keller said.The Microsoft JVM is no longer available for distribution from Microsoft. Microsoft products that currently include the Java software will continue to be retired or replaced by versions that do not, the company said.