Back in 2007 when Apple released Mac OS X 10.5 Leopard, a much-heard criticism
was the lack of support for Java 6. Leopard shipped with an older version of Java, 1.5, even though 1.6 had been released by Sun almost a year prior. Sun had already released Java 1.6 for Linux and Windows, but did not do so for Mac OS X, since Apple insists on developing their own version of Java, according to Sun. Now, 6 months later, Mac Java programmers can rejoice.
Apple has released Java 6 for Leopard, but as was already known, the package only works on the 64bit Intel version of Apple's operating system, so users of early Intel Macs or PowerPC machines will not benefit from this update - even if you have a G5 Quad, no Java 6 for you.
This Java for Mac OS X 10.5 Update 1 adds Java SE 6 version 1.6.0_05 to your Mac. This update does not replace the existing installation of J2SE 5.0 or change the default version of Java.
Get it from Apple's download page.