When comparing MIT/GNU vs Chicken, the Slant community recommends Chicken for most people. In the question“What are the best Lisp dialects?” Chicken is ranked 6th while MIT/GNU is ranked 7th. The most important reason people chose Chicken is:
The Chicken community is very helpful and friendly.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Friendly, welcoming community
The Chicken community is very helpful and friendly.
Pro Well documented
Chicken has easy to navigate and understand documentation that's updated frequently.
Pro Easy to embed
Likewise, FFI is very simple compared to most Scheme implementations.
Pro Compiles to native code
Pro chicken-doc
It has a tool named chicken-doc. With its help you can easily add autocomplete and documentation features to your favorite editor.
Pro Permissive BSD License
Cons
Con Not made to run as standalone
Cannot be compiled to a standalone executable, only to byte code that can be run from the interpreter; and cannot be conveniently interpreted by the interpreter from the command line.
Con Not very well-documented
The documentation is very sparse.
Con Poor Windows support
Con Ill-designed interpreter's interface
The interpreter does not support the use of the left and right arrows to move the cursor in the code and the use of the up and down arrows to navigate through the history.
Con Lacks numeric tower support
The core system currently does not support the full numeric tower. However, there is an extension library available.
Con Lacks proper UTF-8 support
For more detail see http://bugs.call-cc.org/ticket/1374
It's been up there for 9 months, still not fixed.