Now go outside and look at the sky.
The Making Of...
It's interesting to see developers open their programming process to the world on their blogs.
Here are two recent examples that I found while looking for resources on emulator programming (ahem!) - Miggy is a blog from Bristol in the UK and the owner, t0ne, started work on a Amiga emulator in Java in October. He is making great progress - and if I may say so has already produced some of the easiest-to-read 68k emulation code I've ever seen.
And there is Legacy System by Jonners in London, who started on a 6502 / Vic-20 emulator in September and who is also making great strides to bring the ultimate Vic-20 emulator in C# to the world.
I very much recommend both blogs for their great writing about the scary depths and exhilarating highs of emulation programming. Both t0ne and Jonners have a gift to write entertaining about some pretty intimidating coding issues.