IUP is the long-lived, cross-platform native GUI widget library, developed at PUC-Rio, the same university as Lua. IUP’s thoughtful design keep it lightweight and fast (because it uses native GUI widgets) and also make it easy to bind other languages, such as Lua. Adoption of IUP should be great, but the lack of Mac OS X support has hindered it. It’s time to fix this and bring IUP into the modern age. This talk will reveal my efforts to implement 4 new backends for Mac (Cocoa), iOS (CocoaTouch), Android, and a native web browser backend (via Emscripten).