I just wish its cross-platform UIs weren't such a mess. Particularly with its MVCish implementation, it was like it couldn't decide what it wanted to be.
I really really wish there was a good, straightforward desktop GUI for .Net that simply worked crossplatform and wasn't a complete pain in the ass to program.
I really really wish there was a good, straightforward desktop GUI for .Net that simply worked crossplatform and wasn't a complete pain in the ass to program.