The university library here uses the Dewey system for technical literature. Public libraries here use SAB, which is alphanumeric and tailor-made for public libraries.
These days I use neither. I put info in a search box, press [reserve this book] and later pick it up from a shelf marked L (for Larsson). Of course, most of the time I don’t pick it up, I read it online.
Standards are great, everyone should have one!