[barrkel]

I've always been intrigued by the idea that the most reliable software programs are usually compilers.

I don't think this is necessarily true; I used to maintain the Delphi compiler, and there were hundreds of bugs in the backlog that never really got looked at owing to workarounds, low impact and high cost of fixing.

What compilers usually have going for them is that they are batch processes rather than online processes, so they don't have time to build up crud in data structures; they have highly reproducible inputs - code that causes a crash normally causes a crash every run of the program, no weird mouse clicks or timing needed, and this code can usually be sent back to the vendor; and all customer code is effectively a unit test, so feedback from betas etc. is immediate and loud.