I need a WeifenLuo replacement that'll run on both .NET and Mono, on Windows, Linux and Mac, preferrably licensed under the MIT license. I'd appreciate if the API was similar to WeifenLuo's, but I understand that such may not be available.

Also, since I couldn't find anything on Google, I believe this might not exist. In this case, I'd like some hints regarding how to implement this.

I have some(not much) Windows.Forms experience, and I must not use any P/Invoke. I already know out how to detect window motion and how to create a borderless translucent window on a given position and with a given size.

So here are some problems I am facing:

1. WeifenLuo supports multiple left/right/top/bottom panes, allowing them to be resized and contain more than one panel.
2. It also supports splittable tabs.

Is there anything else I should be aware of before starting? Are there similar open-source projects available?