The document discusses strategies for dealing with legacy codebases, specifically rewriting the code completely versus incrementally redeveloping it. It outlines characteristics of software that lasts, such as the ability to evolve over time, separation of concerns, using standard languages, and fault tolerance. Best practices for developing lasting software are also presented, including coding standards, static analysis tools, defensive programming, testing, documentation, and leaving the codebase in a better state than when development started. The overall recommendation is for incremental redevelopment of legacy codebases rather than full rewrites.