Khan Academy
Khan Academy: What to Learn Next
Look into some further learning with HTML, CSS, and JavaScript, which are all evolving technologies.
Wikimedia
Wikipedia: Java Programming Language
A Wikipedia description of the Java programming language.
Other
Antique Maps of the Pacific Ocean: Indonesia Java
Contains five different maps of Java, an island in Indonesia. The map dates from the 1600s and 1700s.
Other
Gemal: Browser Spy
BrowserSpy provides detailed version and support information of Browser, JavaScript, JVM, Java, Plugins etc. Requires JavaScript for operation.
Other
Mcsr: Hints for Web Authors
This site from the Mississipi Center for Supercomputing Research provides a continuously revised report on tips for web design authoring.
Other
Sourceforge: Robocode
Use this programming game, Robocode, to develop a robot that battles other robots.