We live in a modern era of Mac development, but behind that there's 30 years of legacy dating back to the original Mac in 1984. It's easy to ignore the millions upon millions of lines of code that have been written for Mac operating systems from System 1.0 forward, but you do so at the peril of forgetting just how flexible and elegant a framework Apple had developed over the years.
Recently Steven Troughton-Smith — who's best known for his iOS development work — decided to delve into the process of making "classic" Mac OS apps in a modern programming environment. He found some a cool tool along the way:
There has never been a good way to compile Classic Mac OS apps on modern OS X - for the most part, you were stuck using ancient tools, either Apple's MPW or CodeWarrior, running in a VM of some sort. CodeWarrior, of course, is not free, and MPW only runs on Classic Mac OS, which is unstable at the best of times and downright nightmarish when trying to use it for development in an emulator like SheepShaver.
Enter 'mpw' (which I will refer to in lowercase throughout as something distinct from Apple's MPW toolset).
In the course of his discovery and experimentation, Troughton-Smith learned a lot of valuable lessons about Classic Mac OS, Apple's Carbon API, and about mpw itself, which he's now a big fan of. If you're interested in the nuts and bolts of how the Mac works, or if you're a programmer who has an interest in the old days of Mac software development, Troughton-Smith's blog entry is worth a read.
Source: High Caffeine Content