Almost every research project involves programming languages at least indirectly. Some of the projects here more focused on programming languages include:
PLDI - ACM SIGPLAN Conference on Programming Language Design and Implementation - Usually regarded as the premier conference on practical aspects of programming languages.
POPL - ACM SIGPLAN-SIGACT Symposium on Principles Of Programming Languages - Usually regarded as the premier theoretical programming langauges conference.
POPL '01 (London, England, deadline around July 2000)
POPL '00 (Boston, Massachusetts, January 19-21, 2000)