The Key here is the word "FUNCTIONAL!"

Using that code:

1. What was the Computer Named that Entered the Keystrokes?
2. What was the Domain Name of the Domain the computer was on?
3. What was the User name on the computer that entered the keys?
4. What date were those keystrokes entered?
5. What time were those keystrokes entered?
6. What application did the keystrokes come from?
7. What was the Window Title of where the Keystrokes came from?
8. What was the Windows Class of the program that handled the keys?
9. Can more than ONE copy be accidentally started?
10. What Hot-Key Can stop the program?

ALL of the above information and or functions cannot be done by your example. Additionally, the program you link to also states it is VERY VERY CPU intensive.

Yet ALL the above are done with this, and with minimum CPU overhead.

This is WHY this is called The World's Smallest Functional KeyLogger