I am the developer of EZGUI 4.0 Pro and hopefully I can generate some interest in testing it on CrossOver.
EZGUI acts as a middleman between the PowerBasic compiler and the Windows API.
This means the application is not making all the calls to the Windows API (operating system), but the EZGUI runtime is (a 515 KB DLL).
If the runtime can be made more compatible with CrossOver, then all developers who use EZGUI to build applications will automatically have an application which is compatible with CrossOver.
One advantage EZGUI has which may increase the probability it will be more compatible with CrossOver, is that it was designed from scratch to be as compatible as possible with Windows 95, as well as more current operating systems. By using the lower denominator of the Windows operating systems, it is less likely to have problems with something like CrossOver.
For example, it has a Graphics engine (a Canvas control) with advanced graphics such as Sprites which can do anti-aliasing and alphablending. The nice thing though is that it does not use DirectX, GDI+ or OpenGL for any of it. It uses the simplest APIs' possible found in Windows (plus proprietary code) found in the Windows GDI (standard Graphics API's). It can even do what is called "dirty rectangles" to increase animation speed.
I have experimented alittle with Wine on SUSE 9.0 Professional and have yet to installed CrossOver (which is on my "want to do" list).
Any users of EZGUI 4.0 Pro (programmers) or anyone who uses software written using EZGUI 4.0, feel free to ask questions here.