Creator here... Thanks for your comments! There is a full TeXLive distribution on the back end, so all of the packages are there (including beamer, tikz, bibl

Creator here... Thanks for your comments! There is a full TeXLive distribution on the back end, so all of the packages are there (including beamer, tikz, bibliography, etc.). The editor is CodeMirror, so the underlying infrastructure for auto-complete is there; I just haven't had a chance to try it out. I mostly use writeLaTeX for short documents (papers, talks, etc.), so I've never tried it with a 200-page document -- current page limit for the auto-preview is 30, but that's a bit arbitrary.