Prism Launcher is a custom launcher for Minecraft that focuses on predictability, long term stability and simplicity.
Features:
Best Minecraft launcher ever. It was never so easy to install mods and have different instancies of the game at the same time. And it has a cat. Charming and simple UI. And it has a cat :3
I may be old-school, but I like the "classic" UI that's not a web browser and is themeable.