From the MIT Scheme web page:

Scheme is a statically scoped and properly tail-recursive dialect of the Lisp programming language invented by Guy Lewis Steele Jr. and Gerald Jay Sussman. It was designed to have an exceptionally clear and simple semantics and few different ways to form expressions. A wide variety of programming paradigms, including imperative, functional, and message passing styles, find convenient expression in Scheme.

MIT/GNU Scheme is a complete programming environment that runs on many unix platforms, as well as Microsoft Windows and IBM OS/2. It features a rich runtime library, a powerful source-level debugger, a native-code compiler, and an integrated Emacs-like editor.

To reproduce my results on Ubuntu Gutsy Gibbon, install MIT Scheme with

sudo apt-get install mit-scheme

and run the interpreter with

mit-scheme

MIT Scheme makes the following choices:

- Allows the null combination, (), which returns the empty list. (more)
- Evaluates unquoted vectors to themselves. (more)
- Allows the 'sqrt' procedure to return exact results when able. (more)
- Allows the '/' procedure to return exact zero when the dividend is an exact zero, even if some divisors are inexact. (more)
- Supports arbitrary precision literal integers. (more)
- Supports arbitrary precision computed integers. (more)
- Supports the literal syntax for rational numbers (e.g. 1/2 is the literal number one half). (more)
- Supports the literal syntax for complex numbers (e.g. 1+i is the complex number with real and imaginary parts both 1). (more)
- Supports nontrivial exact rational numbers (e.g. (/ 1 3) produces an exact one third, not a floating point approximation). (more)
- Supports nontrivial exact complex numbers. (more)
- Guesses the denominators of inexact numbers per R5RS. (more)
- Propagates division by zero errors from 'string->number' (more)
- Does not define the procedure 'scheme-report-environment'. (more)
- Does not define the procedure 'null-environment'. (more)
- Does not define the procedure 'interaction-environment'. (more)