@ocornut @wjarosz nanogui looks to be opengl only, which is limiting (no raytracing shaders, for example).
If it helps, basically every nvidia, Intel, amd, etc tech demo has the same looking ui, because they all use dear imgui.
It's super popular in game dev, for small things like debug UI in demos, to complex things like making an entire engine's editor UI in imgui.
It's good stuff. It works well and doesn't get in the way.