Hello, I don't know if some of you are familiar with the SFML library (stands for Simple and Fast Multimedia Library) --> http://sfml-dev.org As SDL, SFML is a 2D graphics library, but conversely to SDL it provides a hardware-accelerated drawing, through OpenGL. Well, I'm currently writing its Haskell binding, and I'm stuck with design issues. What I'm heading to is a full IO binding, and that's what I'd like to avoid. I particularly like the way HGL works, with the Draw monad which (IMO) enables powerful composability of the drawings. But HGL is simpler in the way that, for instance, it doesn't deal with images/sprites. So that's why I would like to pick up advice concerning the design of such a binding. First, this is how SFML (in C/C++) works: The main types are RenderWindow, Drawable, Image, Sprite, Shape, Font and Text. An Image basically represents an array of pixels. It is just a resource, and is not directly drawable. An image is loaded from a file, and provides methods for accessing/altering its pixels. Its main purpose is to be bound as an OpenGL texture. A RenderWindow is the window on which the Drawables are... well... drawn. A Sprite, now, is a Drawable. One Sprite is linked to one Image. A Sprite NEVER alters its Image, it just provides positionning/rotation/resizing/colorizing methods that will be translated, when drawing on the RenderWindow, to glTranslate/glRotate/glScale/glColor, etc. So we can see a Sprite as an instance of an Image, since if a same Image is to be drawn 3 times on the same frame, we are advised to create three Sprites of it, which will differ by their position. A Font is loaded from a file, it is a simple resource, just like Image. Text and Shape are Drawables. So, now, questions: 1) For those who know HGL, can the monad Draw principle be adapted to my case? Or am I heading for disaster? 2) How would I handle images? SFML API enables the user to alter the pixels of the image, and I obviously don't wanna copy the entire Image each time a pixel is changed. 3) Is there another library on hackage that handles images in a functional way? (I mean not *all in IO*)