Squeak is a new implementation of the Smalltalk programming environment; it includes among other things: * a rapid-turn-around Smalltalk-80 compiler, * a caching-JIT run-time virtual machine (with full source in Smalltalk), * large class libraries with portable data and GUI models, and * an integrated development environment with coding tools, GUI construction. Squeak was developed at Apple Labs and Walt Disney and has been ported to a variety of computers (including most flavors of UNIX and Windows). Compared to other Smalltalk systems, Squeak has four important features: * Portability (to Mac, Windows, WinCE, and many flavors of UNIX); * Speed (it uses native C for compute-intensive code); * Price (free, including all source code and the right to distribute applications!); and * Sophistication (full Smalltalk-80 language, libraries, and tools).