Open Socialism Is Unproven

‘OS has never existed and there are no examples of anything similar that actually works’.

In fact OS like systems do exist and are proven to work.

Open Source Software

Open source software is free and open software often run by independent groups of people. These people are working for free (although sometimes companies sponsor them) in distributed teams and in many cases are producing software of a superior quality to the private sector.

They are largely working for the prestige. People don’t need massive monetary rewards to want to strive and contribute great work to society.
They typically work completely in the open. All information on decision making, planning etc. is available online.
Like OS they often favor consensus seeking decision making.

The Business World

The business world, which has no restriction on how it manages itself, is continually moving towards cooperative tribal like systems, similar to OS. Tribal leadership is one such movement. The reasoning is that it is more effective if people work together as a tribe, sharing information and knowledge, rather than compete with each other similar to capitalism.

Cooperative Businesses

The Mondragon Corporation is a worker cooperative which has values of cooperation and a relatively even distribution of wealth (executives on average only make 5 times a minimum wage earner which are actually rare since most roles are considered a form of specialization).

Wikipedia

Wikipedia is a great example of people working cooperatively for little personal gain. The only gain is prestige and the sense of being a part of a community.