Annotations

• java.lang.annotation
• Annotations in J2SE 5.0
• JSR-175
• JSR-250 - Common Annotations
• JSR-269 - Pluggable Annotation Processing API

Tools

• Annotation Processing Tool (apt)

Articles

• Aspect Oriented Annotations
• Create and Read J2SE 5.0 Annotations with the ASM Bytecode Toolkit
• Bridging the Gap: J2SE 5.0 Annotations
• Annotations in Tiger, Part 1: Add metadata to Java code
• Using Annotations to add Validity Constraints to JavaBeans Properties
• When to use annotations

Open source projects

• http://annogen.codehaus.org/
• http://backport175.codehaus.org/
• Hibernate Annotations
• http://scannotation.sourceforge.net/

Discussion about Annotations