I've been into woodworking for most of this year, and it interests me how software construction and furniture/house construction are similar and different.

For instance, in the world of physical construction, almost everything is open source.  Look at your desk.  Is it well made?  How can you tell?  Does it do everything it needs to, and if not, could you modify it to meet your needs?

If you wanted to add a desk lamp, would you need to do a patent search first, or consult a lawyer?

Do the joints require a license?  If they did, is there anything preventing you from using an alternative joint?