I've noticed a big trend in php programming (forum design) towards "Responsive Design". I'll paraphrase what I think it means ... essentially it is software that adjusts to different size screens. This has become more important as more people use non-PCs to surf the net (smartphones, tablets). A responsively designed app will "resize and look good" on a wider variety of screen sizes than a traditionally designed app. I would say Synapse has alot of elements of Responsive Design. Does Rebol support Responsive Design well ?
I'd say that I have tried to attain some functionality within the smallest practical screen of 1024x800 ... and as you get a bigger screen, you can do more.