Well d'oh, they're all empty statements, pretty much every language that uses semicolons to finish sentences supports them (I think the only exception is Lua). I have to admit though, when I saw that my first thought was that it was assembly (since semicolons are the usual comment character for assemblers).

These are hilarious. During my undergrad I was working on a partner project and found this in a 20 line .c file:

;;;;;  ;;;;;;  ;;      ;; ;;             ;;;;;;;  ;;;;;;;  ;;       ;;;;;;;  ;;   ;;  ;;;;; 
;;     ;;      ;;;;  ;;;;                ;;       ;;   ;;  ;;       ;;   ;;  ;;;  ;;  ;;   
;;;;;  ;;;;;;  ;;  ;;  ;; ;;   ;;;;;;    ;;       ;;   ;;  ;;       ;;   ;;  ;; ; ;;  ;;;;;
   ;;  ;;      ;;      ;; ;;             ;;       ;;   ;;  ;;       ;;   ;;  ;;  ;;;     ;;
;;;;;  ;;;;;;  ;;      ;; ;;             ;;;;;;;  ;;;;;;;  ;;;;;;;  ;;;;;;;  ;;   ;;  ;;;;;

Which much to my surprise compiles just fine.

(;) is a null statement and usually compiles to nothing at all.

A compiler I was working with for programming MSP430 microcontrollers would interpret a null statement as an actual NOP instruction. If I had pasted that thing into our code a lot of people would have been mad.

Hah. I imagine that in a microcontroller being able to insert NOPs makes sense though (since it's probably something directly controlling hardware).

I ran across that stackoverflow thread years ago I think, and if memory serves my favorite (though there are so many gems in there!) was something along the lines of

// I'm sorry, I'm so sorry.

Sometimes I'm also partial to something along the lines of

// What kind of idiot wrote this?
bad code goes here
// Oh, it was me.

I'm rather satisfied by the fact that the company I work for has a revision control submission tracker thing that keeps track of what people think are the funniest submit comments.

/**
* For the brave souls who get this far: You are the chosen ones,
* the valiant knights of programming who toil away, without rest,
* fixing our most awful code. To you, true saviors, kings of men,
* I say this: never gonna give you up, never gonna let you down,
* never gonna run around and desert you. Never gonna make you cry,
* never gonna say goodbye. Never gonna tell a lie and hurt you.
*/

This one made me lol pretty good

One of the best comments I wrote was something along the lines of...

// Somehow multiplying what *should* be divided is what made this possible so DON'T TOUCH IT EVER

That was in one of my first games I wrote in DarkBASIC Professional. A formula that I used for centering the text manually in my own GUI library was supposed to use division for centering text, but it didn't work. Finally I just randomly tried multiplying it and it worked. To this day, I don't know why, I think it was just a total fluke. :P

/**
* For the brave souls who get this far: You are the chosen ones,
* the valiant knights of programming who toil away, without rest,
* fixing our most awful code. To you, true saviors, kings of men,
* I say this: never gonna give you up, never gonna let you down,
* never gonna run around and desert you. Never gonna make you cry,
* never gonna say goodbye. Never gonna tell a lie and hurt you.
*/

Wow. The rickrolling comment. Awesome!