MzScheme is an implementation of the Scheme programming language for
Windows 95/98/NT, MacOS, Unix, and BeOS. MzScheme is R5RS-compliant.

 MzScheme also provides:

- Pre-emptive threads for all platforms
- Generative structures (a.k.a. record datatypes)
- Built-in exceptions; each primitive error raises a specific exception
- First-class compilation units (modules) for organizing program components
- A class-based object system reminiscent of C++/Java
- Built-in regular expression matching tools
- Simple TCP communication support on all platforms
- Portable filesystem access procedures
- Platform-specific process control, including AppleEvent support