1. Collaborating with non-LaTeX users
tl;dr Overleaf is for LaTeX pros while Authorea is for all researchers
If you are reading this, you probably know that LaTeX is a typesetting system ideal for scientific papers -- but less than ideal for collaborating online with coauthors. Overleaf (formerly WriteLaTeX) brings the LaTeX desktop experience to the web. You compose LaTeX code in one window pane and press compile, then generate a PDF in a separate pane. This is familiar to LaTeX writers (
a small percentage of the scholarly community), but is still difficult for the majority of researchers (those who don't use LaTeX) to grasp.
With Authorea, LaTeX is only one of several formats you can write in. Others include Markdown, and HTML (rich text, like MS Word). Authorea offers a format-neutral, web-native platform. Regardless of the format, you render content on the web -- not in a separate pane. The advantage: you can collaborate with authors who don't know (and will never learn) LaTeX. Authorea's rich text editor is a true WYSIWYG editor (What you see is what you get). It also has the ability to include as much LaTeX and mathematical notation as you need. Every document written in Authorea becomes a beautiful webpage.