Portable Objects for Scheme

POS is a portable object system for Scheme. It offers the following features:

1. It is very portable

   Only uses R5RS standard facilities including define-syntax/syntax-rules

2. Very small

   Consists of only 1 constant, 1 function and 1 macro

3. Supports the following OO features

• multiple inheritance
• class and instance variables and methods
• strong instance and class variable encapsulation
• very easy instance variable access from within methods
• very simple to use
• no MOP but some reflection

4. Open source and freely available