The original title of this site was, as I recall, "TeX, LaTeX, and friends". That seems to have now been trimmed down to just "TeX - LaTeX", but other variants such as ConTeXt are still on topic. How broad does it get?
To be specific, I'm trying to generate PDF documents from PHP. There will be a standard template, but different actual content each time. Escaping values from PHP to produce valid LaTeX looks very very tricky. It would be easy to introduce all sorts of subtle security bugs by missing some escape sequences.
SILE has a similar aim to LaTeX, but has two syntaxes, one intended to be human-editable (and similar to LaTeX), the other based on XML. XML is a mature technology easy to manipulate with a programming language. Using SILE instead of LaTeX may be an excellent idea. On the other hand, if I run into difficulties with SILE, can I ask about them here? Is it on topic?
(A search on Meta for SILE finds nothing.)