"Garry’s Mod, the Source-powered physics sandbox famed across the games industry, is to be sold over Steam for $10 US, with profits split 50/50 between Garry and his team of contributors and Valve. What is currently known as version 9.1 will lose its number and become the initial paid release, while the current version (9.04) will remain as a free demo. All updates will be free. The sanctioned selling of full, third-party mods is new territory for the games industry, and with no sign of Black Cat’s Alien Swarm: Infested it seems that Garry’s Mod will be the first to cross the line.

The practice has both its advantages and drawbacks, and I spoke to Garry to see where GMod falls among them.

"A new GMod with regular updates for $10" is Garry’s summary of the deal for buyers. It’s the cheapest price point Valve maintain on Steam, and the same price as the voluntary donations that have bought keen players banners on scoreboards, enhanced forum features and beta access in the past – although, citing logistics and the gap between buying banners and games, Garry explains that those donators will have to pay again along with everyone else."

- Valve

"Steam might be helpful in that scenario, but exposing GMod to a new pool of players and excluding those who can’t or won’t pay is going to put the community under significant strain, and what comes out when the dust settles will almost certainly be very different, even if that settling takes several months. Garry is optimistic on the matter. “PetitionOnline will probably explode,” he admits, “but eventually I think everyone will see that this is a great move”.

The litmus test of whether or not they do that will be the relative sizes and productivity of the paid and free communities. The two versions will not be compatible, 9.1 being the rewrite it is, and as time goes on the gap between each will grow. Will more people pay than drop out? Will the older credit card-holding audience be as drawn to GMod’s brilliantly silly, ad hoc gameplay? Will the new community without younger players be a better one? Garry certainly thinks so, but what will actually happen is anyone’s guess. The potential gentrification of an online game should be interesting to watch."
- Valve