I used to use a stock Minecraft Server, however I have recently upgraded to a Bukkit server. My question is, how can I move my maps and player files (players inventories and etc.) over to my new server? There is seemingly no 'map' file, and moving the world folder into the new server messes things up and I'm unable to log into the server till I put the stock world folder back. My original server was on a Mac, my Bukkit server is on a PC. I don't think that makes any difference since the files are essentially the same, but just an fyi.
I do not believe you can transfer mac files to a pc. You'll have to start fresh (or get PC versions of your maps)