Duke Nukem 3D is free during the day on GOG.COM

The cult computer game created in 1996 by 3D Realms for one day is free to download on GOG.com for Windows (XP, Vista, 7, 8) and Mac (10.6.8 and above) platforms. The size of the game today seems ridiculous, only 35 megabytes.
Included with the game are offered to download the user manual, volpeiper, ringtone, avatar and artwork. The promotion is valid until December 14, 14:59. Have a nice game.