Agree with d.
Make it .NET and UI-technology independent, I want to use it even if I have a computer with two leds.
And make a Nuget-package please.
That said, if I have to pick a technology mentioned above, I would say WPF, “alla dar i veckan”. In my experience, 99% of the times people prefer winforms before wpf its because they are much more familiar with winforms than wpf. I havent met a developer yet that really learned wpf good that has gone back to winforms*.
Also I’m sure thats its very usefel with a wpf/winform-specific lib that builds on top of that api, but I dont think that has to be from Tobii?
Also 2, I dont know if wpf is a hack underneath as mentioned above, I just think its a really nice way of writing UI, especially when using MVVM-frameworks.
*without threats