F-Script is a lightweight scripting layer specifically designed for the Mac OS X object system (i.e. Cocoa). It provides scripting and interactive access to Cocoa frameworks and custom Objective-C objects. It aims to be a useful and fun tool for both beginners and experts, allowing interactively exploring, testing, and using Cocoa-based objects and frameworks.
Slate is a prototype-based object-oriented programming language based on Self, CLOS, and Smalltalk. Slate syntax is Smalltalk-80-based, rather than trying to be clever and complex. However, the language semantics, environment, and run-time design are all much more powerful than in traditional Smalltalk systems. The design goal is to bring together many excellent existing ideas into one system, and to provide an environment where design decisions in one area don't constrain others.