You can also 'upgrade' to the full game via GOG

The original Diablo still kind of rocks, as evidenced by the fact that Blizzard stuffed the thing into Diablo III as an annual event. But now you don't even need to boot up your GOG copy or buy it, as Rivsoft has made the shareware version of the game completely playable, and painless, in browser form.

Now a lot of you kids might not know what "shareware" is, but it's basically an expanded demo edition of the game (one of the most popular versions of the concept hails from FPS games like Doom) that you were intended to "share" with other people. The rise of the internet, as well as betas and demos kind of killed off the concept, but it lives on today as a relic of the past.

What's really cool about Rivsoft's joint though is that you can "upgrade" to the full edition of the game by connecting your .exe file with the browser edition: so that's an option if you'd rather play in a more convenient window.

Even though I replay the original Diablo every few years or so, seeing that original desktop icon in the browser window really hit me with a wave of nostalgia. This is one of the first ever games I spent hundreds of hours with, a full year before Pokemon Red/Blue arrived in the west.

Diablo [Rivsoft via PC Gamer]