I used to use Factor as my main programming language for a few years and really enjoyed the language and environment. It feels like a mix of Forth, Lisp and Smalltalk. I wrote a number of blog posts about it which might help give a feel for what can be done in the language:
Chris, amazing body of work at your blog. What are your thoughts on the continued maintenance factor and long term viability? what caused you to drop out?
http://bluishcoder.co.nz/tags/factor/