LiquidBounce is open-source and will always be including the different additional tools we make, but this does not mean we have to make use of open-source libraries. We are using proprietary IDEs, propritary operating systems... and of course, we also make use of libraries which depend on proprietary code, but this does not mean it would affect LiquidBounce as open-source project.

Especially our HTML Render Engines are mostly proprietary:
LiquidBounce uses Ultralight (partly open-source)
LiquidLauncher uses Sciter

What are you thinking Minecraft is? Open-Source? Of course not.