This document provides an overview of several agile software development methodologies: - Extreme Programming (XP) focuses on incremental planning, small releases, simple design, test-first development, refactoring, pair programming, collective ownership, continuous integration, and sustainable pace. - Adaptive Software Development is cyclical like evolutionary models and involves speculation, collaboration, and learning phases with short iterations. - Lean development aims to maximize customer value while minimizing waste through practices like eliminating waste, amplifying learning, and continuous improvement.