"Convert your SVG files to PDF and PNG."
homepage, source code: Python with some non-python library dependencies (e.g. cairo2), rendering engine: cairo2, license: LGPG-3.0
"A command line tool to generate PDF from URL, HTML or Markdown files with electron."
"WeasyPrint is a smart solution helping web developers to create PDF documents. It turns simple HTML pages into gorgeous statistical reports, invoices, tickets…"
home page, docs, samples, source code: Python, license: BSD
wkhtmltopdf and wkhtmltoimage are open source (LGPLv3) command line tools to render HTML into PDF and various image formats using the Qt WebKit rendering engine. These run entirely "headless" and do not require a display or display service.
home page, command line (scripting) docs, source code: C/C++, rendering engine: WebKit, license: LGPLv3
Web Browsers, Headless
In the category of headless browsers, there are several candidates which could also be considered for HTML to PDF generation.
For example, ...
### also works with a local file input URL