Perl

Variables

• Scalars
  
• Strings
• Lists
• Arrays
• Hashes
• References
• Misc

Language

• Operators
• Boolean expressions
• Conditionals
• Loops
• Subroutines
• OOP
• Comments

Misc

• Perl style
• Misc

Input / output

• Standard input / output
• File access

Advanced

• Regular expressions
• Pattern matching
• XML
  

Programs

• CGI
  
• Scripts
  
• Modules

Databases

• MySQL