I use ebays Turbo Lister. I'm not exactly sure, but I don't think any other programs exist that allow you to upload to ebay. Turbo Lister is very easy to use. It constantly updates itself and will change its settings to match what you've set through the website (categories and whatnot). You create templates for each thing you want to sell, then you create listings out of those templates. You can switch an item between the various forms of selling ebay offers (auciton format, store format, etc). It has it's problems but it does what I need, and thats uploading 350 store listings a month and about 50 auctions a week.