presheaf takes your xypic diagram and returns a pdf or a png.
Links:
fb oauth https://developers.facebook.com/apps/1784536835187521/settings/basic/
xygyide: http://texdoc.net/texmf-dist/doc/generic/xypic/xyguide.pdf xyjax: http://sonoisa.github.io/xyjax/xyjax.html drawing tex entities: http://detexify.kirelabs.org/classify.html https://tug.org/pracjourn/2007-1/blaga/blaga.pdf mathjax tutorial: http://docs.mathjax.org/en/latest/start.html mathjax doc: https://media.readthedocs.org/pdf/mathjax/latest/mathjax.pdf pdf in html: http://pdfobject.com/markup/ http://stackoverflow.com/questions/291813/recommended-way-to-embed-pdf-in-html