archiving / backing up

what do I need to save to archive so I can re make in a few years time.

Assuming I have pc that still runs the version of arduino

I install libraries like TinyGps into the arduino IDE, which go into one folder, the ide seems to be in another and my source code is in another tree.

any thing I'm missing ?

I'm thinking of backing up the zips of the libraries, and the IDE, then archiving my source code,

anything else ?

I think these are enough..

drjiohnsmith: anything else ?

A version of Java for the operating system of your choice?

BTW: If you just want to be able to burn a new controller with an old program, you just need a backup copy of the compiled .hex file.

Watch the compile messages with "Show verbose output during compilation" enabled and then save a backup copy of the generated .hex file from the temporary directory. Using the hex file you can always upload the "original" compiled program to any board which uses the same type of controller for which the program was compiled.