ShareLaTeX is an online LaTeX editor that aims to as versatile as the top offline editors, while enabling online features such as simultaneous collaborative work and versioning.
Ranked in these QuestionsQuestion Ranking
Pro Simultaneous collaboration
Several colleagues can work simultaneously on the same document, remotely from each other.
Pro Version history
As an online editor, ShareLaTeX keeps track of document versions and what has changed from one version to the next. Reviewing edit history is easy, as is reverting back to an older version if needed.
Con Users need to pay to access all the features
Even though there is a free plan, features such as collaborative work and synchronization with services like Dropbox or GitHub are only available on the paid plans.