An electronic gaming machine architecture is provided in which a gaming platform application and wagering game applications are executed in separate processes but may share access to common display windows; such display windows may be caused to be generated by the gaming platform application, which may then assign specific display windows to the various wagering game applications, along with window handles usable to direct graphical content thereto. The wagering game applications may then direct graphical content to the display windows, while the gaming platform application may retain control over the size, position, transparency, and/or z-order of the display windows.