If you miss those good ol' arcade titles you used to play in your Nintendo Entertainment System, whine no more: NES is back on your favorite web browser!
FireNes is a Firefox add-on that lets you play more than 2,500 NES titles of all times, covering all sorts of interests and styles. Games appear listed in alphabetic order on a sidebar to the left of your screen (if you don't see it, open it with Tools > FireNes), from which this list you can choose the one you want to play and run it with a double click.
The sidebar also includes two other tabs (Top and Favorites) to manage games in a different way. It would have been great to have some kind of search tool to quickly locate certain games though.
When launched, games appear on a small-sized window that runs independently from Firefox. Controls are limited to arrow keys, Enter, Ctrl, Z and X, though sometimes the game does take a while to react to them.
Also, I noticed that some games are a bit buggy, but you can always let the author know by filling in a small form. In any case, FireNes features such a huge collection of games that you'll surely find that one title you were hooked on a few years ago.
With FireNes you can use Firefox for more than browsing webpages: play more than 2,5000 NES games and remember gaming prehistory!