This document compares ASP.NET WebForms and ASP.NET MVC, discussing their pros, cons, runtime stacks, and when each should be used. WebForms provides better RAD development capabilities and control libraries but has UI logic coupled with code, making it harder to test. MVC provides finer HTML control and separation of concerns, making it easier to test, but has less robust control support. The runtime stack for WebForms uses ASPX pages and code-behind classes, while MVC uses controllers and view engines. WebForms is better for data-heavy applications, while MVC is a better fit when test-driven development is needed or finer HTML control is required.