Lua & LaTeX
LaTeX
The Comprehensive TeX Archive Network is the central place for all kinds of material around TeX.
Overleaf is software for running a collaborative cloud-based LaTeX editor used for writing, editing and publishing scientific documents.
PGF/TikZ Manual for Version 3.1.11 - Complete Online Documentation.
TUGboat - TUGboat is the principal publication of the TeX Users Group
Lua
The Programming Language Lua
Lua Tutorial