At the heart of most, if not all, P2P platforms is a commons. But not all commons are the same. It’s good to understand the nuance among them. To help, here is a basic taxonomy: 

1. Inherited Commons – e.g. earth, water, forests – are heavily under attack and becoming scarce commons. It doesn’t have to be this way i.e. in Switzerland, Austria, Japan they are well managed under an agricultural commons, and have been protected for hundreds of years by good collective arrangements between the farmers.
2. Immaterial Commons – e.g. Cultural, intellectual, enabled by the internet, makes it stronger and easier to do than before. Commoning in this sense can be abstract but when we do it around something we care about, whether its free software, open design or wikipedia this really creates a community of shared interest because its something that we all care about.
3. Material Commons – that we which we co create e.g. common stock, common machinery. Think of zip-car, owned by a company but why not have the community own it. Then there is the Commons Car, claimed to be the first open source car, now one of many such projects.”

And here is a running list of commons:

Inherited Commons:

1. Atmosphere Commons ; Atmospheric Commons
2. Energy Commons ; Energy from the Perspective of the Commons‎
3. Environmental Commons
4. Food Commons ; Food as Common and Community
5. Hunting Commons
6. Infrastructure Commons; see also: Developing the Meta Services for the Eco-Social Economy
7. Land as Commons
8. Marine Commons
9. Microbial Commons
10. Petroleum Commons
11. Solar Commons
12. Water Commons

1. Aesthetic Commons [6]
2. Book Commons
3. Communication Commons
4. Cultural Commons [7]
5. Digital Commons
6. Educational Commons
7. FLOSS Commons: see FLOSS as Commons
8. Genome Commons
9. Global Innovation Commons
10. Global Integral-Spiritual Commons
11. History Commons
12. Information Commons ; Information as a Common-Pool Resource
13. Knowledge Commons ; Knowledge as a Commons
14. Learning Commons
15. Libraries as Commons
16. Media Commons
17. Medical and Health Commons
18. Museum as Commons
19. Music Commons
20. Open Education Commons
21. Open Scientific Software Commons ; Open Source Science Commons
22. Patent Commons ; Eco-Patent Commons
23. Psychological Commons

1. Employment as a Common Pool Resource
2. Financial Commons
3. Global Legal Commons
4. Household as Commons
5. Infrastructure Commons
6. Internet Commons
7. Labor Commons
8. Market Commons
9. Neighborhood Commons
10. NonProfit Commons
11. Taxes as Commons
12. Thing Commons
13. Urban Commons
14. Wireless Commons