What packages do you support?

We use TeX Live 2016 on our servers, which provides about 4000 packages, including:

• Figures with pstricks and TikZ. Here are some examples.
• Bibliographies with bibtex and biblatex. Here are some examples.
• Packages, such as fontspec that require XeLaTeX or LuaLaTeX for unicode and font support.

For more details please see this blog post.

Also note that you can upload .sty and .cls files for other packages, for example those from CTAN.