Wikipedia
ShareLaTeX
ShareLaTeX is an online LaTeX editor that allows real-time collaboration and online compiling of projects to PDF format.
In comparison to other LaTeX editors, ShareLaTeX is a server-based application, which is accessed through a web browser. A publicly maintained instance of ShareLaTeX is available at https://www.sharelatex.com, and the software to run a personal instance of ShareLaTeX is available under an open-source license.