Intel Assembly Language
I spent a number of years writing Intel assembler code.
If you don't know what assembler is, don't worry about it. If you do, you'll know that it is becoming a lost art.
If you have programs that run on Intel-based CPUs (basically, your standard PC computer) and they are SLOW, sometimes the answer is to analyse where your code is spending all its time and rewrite those sections in assembly code. Done intelligently, these tweaks can provide amazing speed gains.
