The New to Java Center provides customized learning paths to its collection of links to tutorials, articles, online books, and software downloads. (from SUN)
provides the necessary software to develop and run .NET client and server applications on Linux, Solaris, Mac OS X, Windows, and Unix. Sponsored by Novell.
page has visualizations of some comparison based sorting algorithms. The quick sort, bubble sort and cocktail shaker sort are due to the good folks at Sun Microsystems. The original SortItem applet was written by James Gosling.
blog entry about static code analyzers such as Checkstyle, PMD, FindBugs etc. and focuses on some of the issues that they spot in code. (PDM is great also for C++)