You can perfectly re-submit your code using any machine (the OS is not relevant in this case) from where you have access to your 'C' files: all you need is a working (modern) browser (Chrome would do just fine). And having access to your 'C' files in any computer is pretty trivial if you followed staff's recommendation and placed all your code inside a DropBox
folder.
I use my day-to-day Ubuntu (but could be any OS) to write my code and perform submissions, and it's perfectly fine. For submissions, any OS will do just fine: you simply go to the provided link (in psets specs), and select 'C' files to upload. There's no distinction as to "from where" did those files came ;)
To actually write code, also any OS would do, since all you need is a text editor. But when it comes to compile, debug, and check your code, only then is when you need a set of tools pre-loaded and pre-configured for you in the VM. You could do it in any OS, but with a fair amount of previous work, which is not (still) worth the trouble. Simply use the VM for that ;)
Even check50
should work, since "all" the command does is upload given (as in argvs
) files to a certain folder in a certain server (unless, of course, they've "moved" the server, in which case, we're out of luck ;)