Unfortunately, since I don’t really consider myself a programmer, and I don’t really do any programming, it’s a bit hard for me to say what my greatest application is. I can however tell you of some of the programming achievements I’ve made in my past.
Way back in high school I started out programming using a programming language called BlitzBasic. Over the couple of years I used this language I wrote a number of games, most of them pretty awful. But two games did go somewhere. The first was a side-scrolling platform game I called RollingBall (the main character was a yellow ball). It’s where I first learned about game physics (albeit very primitively) and about how not to write a program (i.e. GOTO = bad). The second was a top-down RPG game in a similar style to the Pokemon games. Although both of these games suffered from a bad case of programmer artwork, they were pretty fun to play (or my deluded variety of fun, anyway).
The greatest achievement I’ve made though was the moment I finally got an operating system kernel that I had written entirely from scratch working on my home computer. It did nothing more than print ‘H’ in the top-left hand corner of the screen… but that’s all it needed to do. Knowing that the code you’ve written is the only code running on a computer system is a pretty awesome feeling.