Thanks for sharing this, I've bookmarked it to check out more later, but from the links you provided, it looks like Chicken Scheme is pretty friendly to use.

I used Chicken for several years in the past and looking at it again recently. Worked great under FreeBSD, Linux, has a large set of well-maintained extensions and has (mostly) excellent documentation. And IME Chicken developers were always willing to answer questions, easily reached on ICQ/mailing lists. That's probably still the case.