This is libsolv, a free package dependency solver using a satisfiability algorithm. The code is based on two major, but independent, blocks: 1. Using a dictionary approach to store and retrieve package and dependency information in a fast and space efficient manner. 2. Using satisfiability, a well known and researched topic, for resolving package dependencies. The sat-solver code has been written to aim for the newest packages, record the decision tree to provide introspection, and also allows to provide the user with suggestions on how to deal with unsolvable problems. It also takes advantage of the repository storage to minimize memory usage. WWW: https://github.com/openSUSE/libsolv