"Nix is a useful system administration tool for heterogeneous
environments and developers who write software supported on
different libraries, compilers, or interpreters.
"Why provide yet another package manager? Because current
package managers fall short in the upgrade cycle. Everyone gets
burnt by software dependencies, at some point. In particular, with
a major release of any given distribution, many people choose not
to upgrade until it is time to do a fresh install. With Nix,
upgrades are always safe: they don't overwrite previously installed
packages. This means previous versions will continue to work, and
you can easily roll back.
"Nix started as an academic project at Utrecht University in the
Netherlands. The name is tongue in cheek; in Dutch it means