The Open Toolkit 0.9.3 Beta Release notes This release introduces Mac OS X support, improves the MouseDevice and GameWindow APIs and fixes several occurences of bitrot in the codebase. Work will now focus on joystick and GL3.0 support. Please report any issues you may encounter at http://www.opentk.com. API changes The MouseDevice.ButtonDown and .ButtonUp events have changed signatures to better conform to the BCL conventions. This is a breaking change. Please change your relevant event handler signatures from: void ButtonHandler(MouseDevice sender, MouseButton button) { } to: void ButtonHandler(object sender, MouseButtonEventArgs e) { } The MouseDevice.XDelta, .YDelta and .WheelDelta properties have been deprecated and will be removed at a later version. Please use the Move and WheelChanged events instead, or track mouse deltas manually. GameWindow.ExitAsync() is no longer available. Please use GameWindow.Exit(), instead.