When comparing Embeddable Common Lisp vs Chicken, the Slant community recommends Chicken for most people. In the question“What are the best Lisp dialects?” Chicken is ranked 6th while Embeddable Common Lisp is ranked 16th. The most important reason people chose Chicken is:
The Chicken community is very helpful and friendly.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Compiles to C
Your code can run (almost) anywhere C can. It is easy to interface with existing C programs.
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 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.