Socialism

I would say so yes, but only if you view it as a communist enclave within capitalism.

The tricky bit is that FOSS exists in an environment that's devoid of scarcity. If I write code and post it under a Free license, you can make infinite copies and use it without depriving me of it. That's rather different from a scenario where I might spend my labour extracting a finite number of carrots from the earth.

Still, I think it's an excellent demonstration that the working class is willing to spend its efforts in a sharing economy... so long as the benefits are reciprocal.