Open-source project?

[Stevie1024]

On the main page 'www.bitcoin.org' it says Bitcoin is a 'community-driven open source' project.

Could anyone let me know where I can join as a developer?

Could anyone let me know on which mailing list/forum board the actual design decisions are discussed and made?

Would it be an idea to put this information on the main page?

[xf2_org]

You don't "join", you just start writing code.

Pull requests are submitted on https://github.com/bitcoin/bitcoin

[bcearl]

There are no more design decisions to make. The protocol is established, the network won't accept changes.

But the client software needs a lot of development, it is missing pretty much every feature one could imagine. Usability and security of wallet management is still bad.