Libsolv is a free package management library, using SAT technology to solve requests. It supports debian, rpm, archlinux and haiku style distributions.
Libsolv comes with a little demo application "solv", which works like a simple package manager. It supports most features of the library like gpg and checksum verification, file conflicts, deltarpm support (in the rpm case).
It also contains language bindings for perl, python & ruby, and example code for each language.
The project has been renamed from "libsatsolver".