I'm not new to the fediverse, but here's an #introduction focusing on just one project:
http://Ora.Network aims to create a global digital #skillsharing network based on the principles of time banking, #libre software, and the #commons. A #mutualcredit currency where 1 ora is added to your balance for every hour you contribute to a qualified libre/commons project. You can then transfer your ora to someone else in exchange for their help working on your own (non-qualified) project.