Open Web Application Security Project. A community which openly trades ideas and techniques to ensure web applications are built securely.
#regularexpressions
Comparing E-mail Address Validating Regular Expressions
Comparing E-mail Address Validating Regular Expressions
Awesome comparison of some popular/suggested regular expressions and how accurate they really are when validating email addresses.
Tech Cheat Sheets
Awesome collection of cheat sheets for all sorts of tech.