...
Basically all of the original BSD Unix ('Lite') tools are available at an interactive login. see /bin, /usr/bin, usr/local/bin. Java. Eg make, gcc, g++.
As shipped, java 1.4.2! For Tiger OS - Install Xcode Tools from the Tiger Installation DVD in order to get the latest gnu tools.
Java
For Tiger OS -
Apple has an update for Java 1.5 : http://www.apple.com/support/downloads/java2se50release3.html
...