Chuck is a type inferencer for Squeak program code. Type inference allows programmers and tools to find the type of a variable or expression in the program. This information is useful directly, and it is also helpful for improving tools like the system browser. For example, the sender-of query can look not only at message selectors, but at queried receiver types, in order to decide which message sends to show the user. Prerequisite: Refactoring Browser for 3.7Prerequisite: MonticelloPrerequisite: ChuckRepository