As described by MW.org, mPDF:
lets [users] export the printable version of a page as a PDF file. To do so it uses the mPDF PHP library (version 6.1), which does HTML-to-PDF conversion.
Advantages of this extension:
- no need to install additional components
- the generated PDF uses the same CSS styles as for rendering the printable version of the page
- small size of the PDF file
- supports UTF-8
Nominated by this contributor (and endorsed de facto by @Robkelk) in this Community noticeboard discussion as a more liable alternative to PdfBook, which struggles big-time with UTF-8; generates empty output (at least where I was two months ago); and remains on the chopping block per UO.
As mentioned before, the likes of this extension would sure come in handy for my future books. Let's hope the situation actually gets rectified soon enough in a test run....
Also on my current roadmap: Semantic Result Formats (T9542).
[1] Hosted on GitLab; last updated in July 2021.
[2] This actually happened once before (in April 2019 -- R9:6156f8d2f39e); almost two years later, the extension was reinstated via T6996.