Manage Your Research Identity and Track Your Impact

A social network for Academics, with many Facebook-like features. You can upload publications you own the rights to and track who reads them, post updates or notes, join groups based on research interests, and follow other academics.

A similar service to Academia.edu, with similar features. Which one to use comes down to personal preference.

Mendeley is best known as a reference management tool that helps you build a personalized library of research and format your references as you write. However, the web profile has many social features. You can follow other authors, and create groups to collaborate with other researchers (the free version of Mendeley only allows for one group with up to three people). As a social network, Mendeley has fewer features than Academia.edu and ResearchGate. It's probably only worth creating a profile if you're already using Mendeley for reference management.

LinkedIn is a social network for professionals in general, not academics in particular. It lacks some of the features of Academia.edu and ResearchGate (you can't upload publications and get metrics on who's reading them). However, you can add a list of your publications. LinkedIn might be most useful for grad students looking to work in industry after graduation, or for researchers looking to develop industry or government connections.

GCcollab is the Government of Canada's collaborative tool designed to facilitate communication and knowledge sharing between public servants, academics, and students at Canadian Universities.