Use knowledge to:

• understand how compilers work (use them better)
• gain experience with building complex software
• build compiler for your next great language
• extend language with a new construct you need
• adapt existing compiler to new target platform (e.g. embedded CPU)
• regular expression handling in editors, grep utilities
• build an XML parsing library
• process complex input box in an application (expression evaluator)
• do simple natural language processing (parse sentences)

Prove that you got the knowledge

• Obtain 6 credits
• pass GRE Subject Exam (e.g. questions on LR parsing)

Most importantly:

• Have fun!