Flare is an open source game development framework written in C#, designed to allow the user to focus exclusively on their game design rather than the drawing or other areas of their game. Also check out Flare.GUI, a small library that uses Flare for simple GUI rendering.
Changelogs:
v1.1.1: Adds access to keyboard and mouse events, icon, vsync setting. Also adds color constructors to Sprite and Text classes.
v1.1.0: Major (breaking) API refactor (hides OpenTK GameWindow)
v1.0.1: 2D text rendering and sprite rendering capabilities, using images loaded from file using System.Drawing and fonts compiled using AngelCode's BMFont, http://kvazars.com/littera, or any other compatible system.
For feature requests, issues, or contributions (which are welcome!), check out the Github page, https://github.com/WardBenjamin/Flare.Framework.