[simonw]

Good luck compiling an iOS app you built and last touched in 2012 against a modern version of XCode.

You'd need to keep an entire old, un-upgraded Mac around just to have a chance of doing that without MAJOR engineering work!

[Wowfunhappy]

What about a Virtual Machine? I've found VMWare Fusion does a good job with Mac guests. Snow Leopard works quite well. You could even do it from a non-Mac host if you don't mind applying well-known patches to VMWare.

[wingerlang]

I think the best solution is to just keep both, I have all the source code for all my projects since maybe 2008. But I also keep a lot of screenshot, if I want to refer to an old project I go to those screenshots (or even better, videos) in 99.9% of the cases.