Do you have to have Unity Pro in order to zip/unzip files. If so, is there any other compression system that can be used by the indie version? Thanks much in advance.
Update: Apologies. I was referring to from within a game.
This is already answered here. (At the absolute worst, you could write your own unzip code, but there are libraries that do it. You don't need Pro for managed code libraries.)
You can create unitypackages with unity (Assets->Export Package...). Zip files are created / opened with 7zip or winzip or pkzip or pakrat or five krabillion other programs :)
As far as I can tell, yes, you would probably need to have the pro version - because with that, you get support for plugins, which should allow you to use the entirely free zlib (written in C/C++) source within your game.
I have seen a C# port of zlib, though, so, assuming there's a way for the free version of Unity to write to a file, you might be able to hack this with a script. Only trouble is, I haven't seen any mention of how to do file read/write in the ref manual, so my guess is that it isn't supported, unfortunately.