A software reconciliation engine utilizes a software rule-based catalog to produce accurate license reconciliation across a wide range of software configurations. A software offering may comprise software installables and corresponding constraints. Installed software and active hardware is discovered by a scanner, stored in an installed software database and active hardware database respectively and is mapped against entitled software offerings to determine whether the installed software is entitled to be installed on the hardware. The installed software has a base product attribute, a used-in-count attribute and a parent-child attribute that are used by the reconciliation engine to compare against the constraints to determine entitlement and report compliance.