This document discusses and compares various software development methodologies. It describes the Waterfall model, Prototyping model, Incremental model, Iterative model, Spiral model, RUP, XP, Agile, Scrum, Lean, DSDM, RAD and FDD methodologies. It explains that a methodology provides a formalized or systematic process for creating software. Methodologies can be sequential like Waterfall or iterative like Agile approaches. The document also gives overviews of specific methodologies like Scrum, Lean, XP and DSDM.