This document discusses UI prototyping using Smalltalk. It summarizes: - Pierre Laborde and Eric Le Pors are UI experts who have over 12 years experience with Smalltalk prototyping. - Their tool, SMOCK, allows for rapid prototyping of UIs through a live and intuitive modeling language. It can simulate realistic user environments. - SMOCK has benefits for prototyping like live modifications, an intuitive language, multi-platform support, and including everything in one file. It includes components like a 2D engine, UI widgets, and tools to design without code.