The Dear ImGui C++ API also maps very well to C, so well that I actually prefer the C-API when working on a project that's mostly C (instead of using C++ for the UI code and C for everything else as I did before). AFAIK most of the other language bindings are also based on the C-API (which is autogenerated from the C++ API):

https://github.com/cimgui/cimgui

We recently started to use Dear ImGUI in our custom game engine. Before we used Unity which has its own immediate mode gui solution. And I have hard time to switch. I don't know if I don't understand how Dear ImGui work yet in comparison to Unity's one but it feels so limited.

So main difference is that Unity is multipass (it calls your gui drawing code multiple times per frame) and because of it it supports horizontal layout, vertical layout, custom layout modifiers, styles and it is easy to use

in Dear ImGUI I am struggling to write stuff like:

layout 3 controls horizontally, allocate fixed size for first and last one and use all left space for middle one

or

layout next N controls vertically of unknown height and use this background color for them, then layout another set of controls and use different background style for them

I am not the person who was actively working on integration it into our engine, so maybe it's the problem of not having documentation on our wrapper...or me not understanding very basics of it

Talk to occornut! He even posts here. Surely you gonna get some reasonable reply, or at least something. Also consider supporting him! Raise an issue on github, or look for similar before hand. I'm also torn when comes to dear imgui, but keep reading updates on it, and trying it at least few times a month with small things.

honestly, im pretty sure imgui can't help you here, i.e. you have to calculate all the necessary sizes/positions yourself and tell imgui where everything should be

Cool. Does that mean I can use this in a C# Console app?