The open source community created something magical that I don't think had existed before.

People all around the world helping each other to create better things, for free, just because they can and want to.

Utopia would be something like that in my mind. Required jobs would be automated completely, things like cleaning, delivery, and other services like police, fire fighters, etc. All of that would be taken care of by machines and software at a minimum costs, which is covered by the running costs of the city, which would be small.

Each person gets allocated a minimum amount of money that provides them with shelter and basic food. Basically a large majority of people would simply exist in this reality. They simply live their lives with all their basic needs covered.

A small minority will be free to to whatever they want. This will allow them to create multiple things and share them with the world. Discoveries, new science, new advances in services, anything really. Think about how open source has dramatically changed the world, and think how adding much more people to that philosophy would give us as a species.

There are a few people that do the vast majority of things, the utopia would amplify this effect freeing talented people from their mundane jobs they have to do now to be able to have a roof over their head and some food to eat.