Cacao

Pure Swift Cross-platform UIKit (Cocoa Touch) implementation (Supports Linux)

Build

OS X

brew install cairo sdl2 lcms2
swift build -Xlinker -L/usr/local/lib

Ubuntu

sudo apt-get install libcairo-dev libsdl2-dev liblcms2-dev
swift build

Screenshots

Run PaintCode StyleKits in Linux

Hardware-accelered UIView animations

Layout views according to a UIViewContentMode

Create applications that run in the native Window Manager