DJVU is raster format. It's intended for scans and archiving printed media. It's possible to use it for documents produced digitally, but I don't think it will be a good idea.
PDF "core" is not that bad, but 90s "multimedia" craze turned it into badly designed graphical application runtime.
Thanks for disambiguation, the raster-vector part is really a major difference. Is PS a viable alternative (even though it is a programming language itself)?
AFAIK, PDF is mostly a container for PS with compression and better handling of fonts (BTW, can fonts be embedded in PS? How fonts are sent to printer?).
Still, both formats are too much printing-oriented. Reading documentation in PDF on computer screen is not especially pleasant, and unbearable on phones.
PDF "core" is not that bad, but 90s "multimedia" craze turned it into badly designed graphical application runtime.