From the RScheme web page:

RScheme is an open-source (and freely redistributable) implementation of the Scheme language with lots of extensions and additional features beyond the core language.

To reproduce my results on Ubuntu Gutsy Gibbon, install RScheme with

sudo apt-get install rscheme

and run the interpreter with

rs -q 2>&1

RScheme makes the following choices:

- Has a case sensitive reader (that I could not turn off). (more)
- Does not provide the 'syntax-rules' macro system. (more)
- Allows variables to be set with 'set!' even if they have not been defined with 'define'. (more)
- Allows forcing non-promises. (more)
- Treats recursive forcing naively. (more)
- Allows division by inexact zero. (more)
- Allows inexact division by zero. (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)
- Defines the denominator of an inexact number to be exactly 1. (more)
- Propagates division by zero errors from 'string->number' (more)
- Does not define the procedure 'angle'. (more)
- Does not define the procedure 'magnitude'. (more)
- Does not define the procedure 'transcript-on'. (more)
- Does not define the procedure 'transcript-off'. (more)
- Does not define the procedure 'port?'. (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)
- Does not define the procedure 'rationalize'. (more)