The State of Our Art
Roleplaying as a self-aware form has only been around for about three decades. In that time it's been through three distinct "generations." These generations can by no means tied to a specific system release or year... they've grown naturally as the art of roleplaying has matured. By this reckoning the Window would be considered a third generation roleplaying system.
First generation roleplaying is dice and maps and little metal figures. This is where it all began. The Game Master describes the setting room by room and typically the characters wander around with swords or guns killing things and accumulating money and ever bigger weapons. It's all very childish, but admittedly it can be fun once in a while.
Somewhere along the line, someone (probably lots of someones, simultaneously) discovered that the scope of roleplaying can be a lot larger. The systems started being more universal and the characters more unique. Tactical maps disappeared for the most part, and everyone started focusing on characterization and plot. Out of this perspective exploded a whole slew of new roleplaying genres... horror, espionage, romance, wild west. This is second generation roleplaying, where most mature roleplayers fall today.
In recent years (or considerably further back in some cases), there has been a movement to push roleplaying to yet another level, its third generation. The lines between PCs and NPCs, live-action and table-top, even Gamemaster and player, are blurring. Card tables covered in dice are giving way to candlelit dinners and dramatic background music. The stories being told are on par with "real literature," and players in a game have been replaced by actors in a very intimate drama. These people are interested in constantly trying new structure and experimenting with the potential of the whole roleplaying medium. The Window has developed out of this atmosphere.