This document provides an overview of the evolution and key versions of the Oracle Primavera P6 project management software. It begins with the origins of Primavera Project Planner (P3) in 1983 and discusses major milestones like the releases of P6 v6 in 2007, P6 R8.0/8.1 in 2010-2011, and P6 R8.2/8.3 in 2011-2013. The document also includes a table that summarizes the new features, supported databases, security, workflows, reporting, and upgrade paths for different P6 versions. Common issues with upgrading between versions like new components, database upgrades, and discontinued features are also outlined.