None of the so called alternative communities I have known really satisfy that concept in terms of living 'for free'.
All require input of one kind or another, there are a lot of skills within a pool of people, and each can be bartered and used for the good of the community.
For example, often in such a community a qualified Lawyer will continue in that profession, and make more of a financial contribution, whereas someone unskilled might directly work within the community.
They certainly do operate successfully within Britain, and there are many of them.
It is not all about free sex and drugs.
Some of the communities in London are really just organised housing collectives where people want more control over who they share their living space with.
I lived in a large shared house at one time, a long time ago. Some of my housemates decided they wanted to live together longer term and formed a collective and sought out a property which they purchased from the council and are still in ownership twenty four years later.
The 'membership' has changed now and then, but really it is just a bunch of people who work independently but contribute collectively to the group, and share space.
Not really complicated.
A lot of the larger collectives are along the same idea, for example where a group have all wanted to live off the land but individually could not afford to buy a sustainable amount of land, so have made a collective purchase and built affordable group accommodation, in lieu of expanding as funds allowed to provide individual homes to those who want it, often long term members and those starting a family.
The quality of life on offer often far exceeds that a family in a similar financial situation might afford otherwise.
I tend to find the communities arranged around strict communal ideals and religious tenets uncomfortable and unnecessary.
For me, it is really just a version of the croft system I grew up with, where me and my brother would be sent to the neighbours to work, and in return he would lend us a bailer, and the vet who lived next door would come and aid us in calving or whatever in return for our hospitality and the odd bottle of malt.
Tied accommodation on estates, etc. is problematic as often the workers have poor pay and conditions, and are subject to eviction if they don't toe the line.
Not always the case, but often enough to be wary.
It is ironic that this subject elicits some of the responses that seem negative, after all Retro Bike with all the aiding and assisting each other and socialising around a shared interest/lifestyle is operating exactly like many 'alternative' communities.
The idea of pooling your effort, for example going to get a frame for someone and posting it for no other reward than that of helping a fellow Retro Biker, is one of the core values in most 'alternative communities'.
So, like it ir not, if you are reading and writing in this site you are quite likely already the member of an Alternative Community.