I am currently writing a book using this Latex Template https://www.overleaf.com/latex/templates/nice-arabic-book-template/qttfgxhqbwkc licensed under The LaTeX Project Public License.
Can I print and sell the book that I wrote using this template, provided that I mentioned in the book that I used this template? Also, are there any restrictions? I thought about contacting the original author PASQUET Stéphane but I couldn't find his email! I appreciate any help!
I think the license language is a bit messy and difficult to apply to templates for documents. Based on the definitions contained in the LPPL, your book is a 'Derived Work' of the template you are using. I am not an expert on LaTeX Templates, so I am assuming they are similar to WORD templates.
Exporting a document into anything a printer would understand (i.e. a page-description language such as PDF) is not explicitly mentioned in the license, but the language related to 'compiling' or 'Compiled Work'.
Section 10 of the license allows you to distribute the Derived Work under a license other than LPPL.
a. A Derived Work may be distributed under a different license provided that license itself honors the conditions listed in Clause 6 above, in regard to the Work, though it does not have to honor the rest of the conditions in this license.
b. If a Derived Work is distributed under a different license, that Derived Work must provide sufficient documentation as part of itself to allow each recipient of that Derived Work to honor the restrictions in Clause 6 above, concerning changes from the Work.
Way back in the license document you can find these words:
Derived Works That Are Not Replacements
Several clauses of the LPPL specify means to provide reliability and stability for the user community. They therefore concern themselves with the case that a Derived Work is intended to be used as a (compatible or incompatible) replacement of the original Work. If this is not the case (e.g., if a few lines of code are reused for a completely different task), then clauses 6b and 6d shall not apply.
The above is applicable to you, as your book is by no means trying to replace the template (your book is not a template).
So where do we stand now? You may distribute your Derived Work (LaTeX file of your book) under a license different from LPPL. This is good for you, as you can then select any license or even a 'all rights reserved' and sell it in paper or digital format. You only need to comply with Section 6 conditions, where 6b and 6d shall not apply and 6a ("If a component of this Derived Work can be a direct replacement for a component of the Work ...") is also not applicable, so only 6c is left, which should be easy for you to comply with.
When you translate/export your LaTeX file (the book) into PDF, the LaTeX file is already under a different (your) license, and you can ignore the requirements and conditions stated in Section 7 of LPPL.
