Just asking on behalf of someone else, and it's something I should know anyway. I imagine everyone here uses something that's already incorporated into their own game to some extent, however I'm interested in anything from the next step after paper & pencil. Anything people recommend that works as a standalone for simply viewing a design that won't necessarily need to be turned into a playable world? Heck maybe even Photoshop if you could force it to snap to grid and paint with selectable pieces. (Can it?) From what I've found, OGMO (http://www.ogmoeditor.com) and Tiled (http://www.mapeditor.org) sound ok, or maybe Mappy (http://tilemap.co.uk/mappy.php). Comments? Other suggestions? Cheers.