Ask HN: Linkedin alternative

We all love to hate Linkedin but it does have some value in terms of connecting with co-workers specially from the past. Yes, recruiter noise is bad.

What if there was a linkedin alternative which was free of recruiter noise but a more closed network where you could connect with people you choose to including your co-workers or even new contacts. Would you want to use something like that ? I always wonder if there was a linkedin alternative, what would that look like ?