Patterns

I love this word 'Patterns', It kind of summarizes everything that we learn in IT world. We have seen so many categorizations of patterns over last 10-15 yrs -
Design Patterns (GoF , Gang of four)
J2EE Patterns
EJB Patterns
SOA Patterns
Architecture Patterns
Integration Patterns
Application Patterns

In 2003, my friend Satya and I used to write a tutorial on GOF Patterns, Its still available here