The issue I want to raise is what is at the focus of the study of programming languages. By this I mean, what is the thing (or things) programming language researchers study. I do not want to discuss what should be done, at the moment, but rather orient outsiders about the actual practice in the field.

Specifically, my aim is to explain which aspects of languages are studied, and to let people know how these research areas are called, and perhaps where to find more information about new results etc. I am not thinking about specific lines of research, but rather about the kinds of things researchers study.

My intention will hopefully be clearer after reading my answer to the question in the title of this post:

Most of the time, programming language theory (PLT) is concerned with the semantics (i.e., meaning) of specific programming constructs. Much less outstanding research is done on other aspects, such as syntax, implementation and runtime issues, and languages as wholes (compared to the study indvidual constructs).

This is, of course, a very incomplete answer to the question. Let the discussion begin...