I am one of the earliest members of the EuLisp group that designed a new dialect of Lisp described in many details in a recent issue of the "Lisp and Symbolic Computation" journal. The goals of EuLisp were presented in LFP86.
Greg Nuyens and I explored the semantics of identifiers in TR89a.
I also tried to explore the realm of language design by myself with RL89 (standing for Reasonable Lisp).
Finally, I worked on modules and macros with Julian Padget in a series of papers BCG90 and ICCCSS91.
Design of macros and first-class environments also appears in the book but are further refined in, respectively, REFLECTION96 and ICFP96.