Sun's posted a minor maintenance update to the Java 2 Software Development Kit 1.4.2, version 1.4.2_08. This version fixes a couple of dozen assorted bugs. It's available for Windows, Linux, and Solaris.
Excelsior has released JET 3.7 MP1, a Java virtual machine for Linux and Windows that uses a combination of a traditional machine code compiler and just-in-time compilation from byte code. This release adds support for Java 1.4.2_08 and fixes bugs. JET costs start at $150 and run up to $3375 depending on which version and how much support you want. Even when you pay for it, support is available by e-mail and Web site only.