Travis has been working on some cool platform linkups recently:

A new version of Cairo has been posted. Under some guise, I have had this working under each of the three major display platforms. I've been able to do Cairo things under live Windows windows, and now I've got X11 windows (and pixmaps even) working. And Aqua pretty much works. With the annoying notion that you have to cover the window to get it to update properly. :) That should be easy to fix I hope. For Windows I need to chase down why the surface goes stale often after a pop up menu has obscured it. And under X11, some VW floating point ops if followed soon by certain cairo calls don't behave as expected. Something about some floating point flag. These are all surmountable hurdles though. And any other person that was properly motivated would be more than welcome to load and help fix these issues. It's time for me to start putting together my Cairo presentation for Smalltalk Solutions. I'll be doing it in... Cairo of course.

You'll also want to read this, and this.