| > Peter Aachten goes further. Based on the Clean group's experience, he | > thinks we can not only define a satisfactory (A), but also define a | > lower-level interface (expressed in the C language) that | > suffices to support (A) | > and yet contains no target specific code I phrased this badly. What I meant was this. Let's call the lower-level interface (L). Let's call the thing we are mapping to the "target". A target is either a portable library like GTK, or a native UI platform like Windows. A target is something we don't implement. The goals of (A) are: Reasonably easy for programmers to use Programmer's interface does not change across targets Rich enough to be useful The goals of (L) are Reasonably easy to implement (but maybe less easy to program with) Programmer's interface (from "above") does not change across targets Rich enough to implement (A) As I understand it: ObjectIO and Daan's Graphics.UI.GIO are examples of (A) Daan and Krasimir's Port is an example of (L) When I said "contains no target-specific" code, I meant that the code that implements (A) using (L) is not target specific. The implementation of (L) will certainly be target specific. You are right that (L) does not need to be written in C. Indeed there might be many implementations of (L): some which are entirely in Haskell (perhaps implemented by you), others written mostly in C (using existing libraries). I know little about particular UI libraries. My suggestion, though, is that we focus discussion on what (A) and (L) should look like, rather than on how they should be implemented. Simon