Debugging tools are provided for program objects in dynamically typed programming languages. Some dynamic objects have both static type members and dynamic type members. Some dynamic objects implement an IDynamicObject interface, and some include a COM object. A list of dynamic object members is obtained from a dynamic language runtime. Member values are then obtained, and displayed in the debugger. Properties can be added to a dynamic object in the debugger. Code can be generated during debugging to make a user call to a method of the dynamic object, to evaluate a property of the dynamic object, and/or to forward a behavior of an operator to the dynamic type of the dynamic object. In some embodiments a dynamic language runtime operates with the debugger.