ShareLaTeX!

Overleaf, formerly WriteLaTeX, is a collaborative writing and publishing system that makes the whole process of producing academic papers much quicker for both authors and publishers.

Texmaker is a free LaTeX editor, that integrates many tools needed to develop documents with LaTeX, in just one application.

Authorea is the online document editor for researchers that allows researchers to write, cite, host data, and publish research documents. Authorea is trusted worldwide by leading researchers writing and publishing content in every discipline, from astrophysics to zoology. The online document editor supports a wide range of markup languages (richtext/Word, LaTeX, and Markdown) and scientific integrations, including the most popular citation management, graphing, and visualization plugins. Authorea is on a mission to accelerate science through a superior web-based research-writing platform that delivers the power to write and publish in a web-first world squarely to the author.  »

Fidus Writer is an online collaborative LaTeX editor especially made for academics who need to use citations and/or formulas. The editor focuses on the content rather than the layout, so that with the same text, you can later on publish it in multiple ways: On a website, as a printed book, or as an ebook. In each case, you can choose from a number of layouts that are adequate for the medium of choice.

VerbTeX is a free, collaborative LaTeX Editor for your Android device. It allows you to create and manage LaTeX projects directly on your Android device and generate a PDF by using Verbosus (Online LaTeX and Octave Editor)

Swift Calcs enables users to effortlessly create and collaborate on interactive computational documents, from any device. Swift Calcs is bringing modern cloud­based, user­centric design paradigms to computational software.

Write and compile LaTeX online.You need only browser and Internet access to typeset LaTeX documents and compile them to PDF.

\BlueLaTeX provides a full-featured server that allows you to create, manage and collaboratively edit documents written in \LaTeX. A web client is also provided to use the features served by the server directly in your browser. A Restful API exposes all possible operations that can be performed on the server side, which makes it possible to use any editor that can communicate with this API (basically any editor that can issue HTTP requests) to become a \BlueLaTeX client.

As an integrated environment, TeXpert allows users to edit, compile (generate PDF output) and view the result within a single app. As a result, it provides the convenience and productivity because it eliminates the hassles of switching back and forth between different applications. In this context, one does not have to open, say TeXPortal, to (re)compile the document and wait for it to complete then open generated PDF with another app; finally using Android's Recent apps button to go back to continue editing the file. »