ThinLisp is a practical dialect of lisp for real world applications. You develop in Common Lisp, you deploy in C. ThinLisp programs are as fast as C, by design. Used for a decade in million line systems.
Kawa is a full Scheme implementation. It implements almost all of R5RS (for exceptions see Restrictions), plus some extensions.
Genworks (www.genworks.com) now offers a stable commercial GDL.