stamps.com software. What the ****, I mean seriously it is so terrible. I would just use the site only, but strangely it doesn't give the same options and prices for things, more expensive and a lot of the time missing first class option for no damn reason. The other thing that really angers me, is I can't choose the fast economy printing option in my printer when using the stamps.com software. So every label takes like 10 ****ing minutes to print on photo quality or whatever the hell. Yeah, first world problems.