Other package management systems do one or two of the following things, but I haven't found any that can do all three at once, other than pkgsrc: 1) have good availability of pre-built binary packages for most platforms 2) facilitate building of packages directly from source, whether on non-mainstream platforms / architectures, and / or with or for the purpose of non-default package options 3) unprivileged builds / i…
nix does all three of these, I think.
Do you have more information?