What Namespace to choose for Open-Sourced .NET Frameworks?

Is there a preferred way of naming opensource libraries and frameworks in the .NET field? I've seen many different kind of things, but is there one to rule them all?

Which one (if any) is the preffered way?

• GitHubUsername.Project GitHub username and project name
• Project just the project name
• Project.Component1 when managing many different libraries in one repository

So, what are the best practices?