Apple this week released an update to its Java Virtual Machine, taking users of Mac OS X 10.4 Tiger and 10.5 Leopard to 1.6.0_07. Depending on your operating system, the patch fixes as many as 27 bugs, and chances are pretty good that you'll benefit.

There are separate updaters for Tiger and Leopard, or you can simply run Apple's Software Update and let the OS figure it out. If you're not sure whether you need to upgrade, an applet at the JavaTester.org Web site will help you find out which JVM version you're using in the browser that you use to visit the page.

While Sun updates JVMs for Linux, Solaris and Windows, and fixed many of the defects in the Apple update months ago, Apple maintains its own JVM, and was left to fix the Mac-only vulnerabilities. The most critical of the bugs reportedly permit crafted Java code to be executed remotely by visitors of Web sites containing the malicious code, according to an Apple security report.

The update brings Java SE 6 to v1.6.0_07, Java SE 5.0 to v1.5.0_16, and Java SE 1.4.2 to 1.4.2_18. According to Apple, the update for Leopard "delivers improved reliability and compatibility for Java SE 6, J2SE 5.0 and J2SE 1.4.2 on Mac OS X 10.5.4 and later," and for Tiger does the same "for Java 2 Platform Standard Edition 5.0 and Java 1.4 on Mac OS X 10.4.11 and later." The release supports all Intel and PowerPC-based Macs; Java SE 6 for 64-bit supports only Intel-based Macs.