Lambda the Ultimate

A short essay by Tom Van Cutsem, Why Programming Languages?:

When I present my research work on programming languages, people often ask me "why do you need a new programming language to solve this problem? Why not just implement it as a library?" Or, I get asked "why didn't you implement it as an extension to {some existing language}?" In this essay I try to make explicit some of the goals and motivations behind language design.

Van Cutsem is the author of AmbientTalk, which has been discussed obliquely on LtU a few months ago.