If there are any .NET developers interested in a project I can recommend looking at the Catalyst protocol project.
Website: https://catalystnet.org

Github
The Catalyst organisation on GitHub can be found at https://github.com/catalyst-network
There are 33 projects within the organisation, not all are public yet but some links you may find interesting are below.

https://github.com/catalyst-network/Catalyst is the main Catalyst protocol repository which includes instructions for building and running a node on the test network.
https://catalyst-network.github.io/Catalyst/api/ provides some API documentation for building on top of the network.
https://github.com/catalyst-network/Community/tree/master/governance describes our approach to governance. This is being further populated this month with committee members.
https://github.com/catalyst-network/Community provides more community information.
https://github.com/catalyst-network/Community/blob/master/CONTRIBUTING.md provides contributor guidelines.

There's also an additional 43 repositories in our Atlas City Github organisation although most are closed source. https://github.com/Atlas3T

Test network
Node explorer at http://catalystexplorer.z33.web.core.windows.net/dashboard/#/
Block explorer at http://catalystexplorer.z33.web.core.windows.net/?network=Node%201

Both of the above are better in dark mode which entails clicking the sun symbol in the top right of each page.

The simplest way to access the test network without building nodes is using the test network web wallet.

http://wallet.catalystnet.org/

Coins on the test network can be obtained from the faucet at catalyst-faucet.herokuapp.com

Other links
YouTube channel: https://www.youtube.com/channel/UC1lqdhBey7W_GAfb21dTpng
Discord channel: https://[Suspicious link removed]/catalyst-network