I would like to add that if you have access to the TeX-like source code, probably LaTeX. For example, you want to read preprints fetched from arXiv of which you can download LaTeX source code. In this case, you can have a try to take advantage of tex4ebook, which compiles LaTeX source code to epub and mobi ebooks which you can send to ebook readers like Kindle.

The easiest command to compile is:

tex4ebook -f epub+dvisvgm_hashes [filename]

or you replace epub by mobi if you want to compile a Kindle ebook (you need kindlegen for that). dvisvgm_hashes is used to generate svg, Scalable Vector Graphics, pictures for equations etc, better than png pictures. It does not work perfectly, but usually with a bit of hacking and modification of the LaTeX source code, I can get an ebook file. I sent hundreds of papers and lecture notes to my Kindle, and it works for me.

I would like to add that if you have access to the TeX-like source code, probably LaTeX, there is usually a good solution. For example, you want to read preprints fetched from arXiv of which you can download LaTeX source code. In this case, you can have a try to take advantage of tex4ebook, which compiles LaTeX source code to epub and mobi ebooks which you can send to ebook readers like Kindle.

The easiest command to compile is:

tex4ebook -f epub+dvisvgm_hashes [filename]

or you replace epub by mobi if you want to compile a Kindle ebook (you need kindlegen for that). dvisvgm_hashes is used to generate svg, Scalable Vector Graphics, pictures for equations etc, better than png pictures. It does not work perfectly, but usually with a bit of hacking and modification of the LaTeX source code, I can get an ebook file. I sent hundreds of papers and lecture notes to my Kindle, and it works for me.