We are proud to announce that Garry's Mod, the number 1 sandbox for the Source engine, will soon feature full support for Nuclear Dawn.
Our development team is working with Team Garry to include Nuclear Dawn in Garry's Mod, so you can play with Nuclear Dawn's content to your heart's content.
What is Garry's Mod?
Garry's Mod is a physics sandbox. Unlike regular games there aren't any predefined aims or goals. GMod gives you the tools and leave you to play. You spawn objects and weld them together to create your own contraptions - whether that's a car, a rocket, a catapult or something that doesn't have a name yet - that's up to you.
More info about GMod can be found here.