TCOL

from The Free On-line Dictionary of Computing (8 July 2008)

TCOL

   CMU.  Tree-based intermediate representation produced by the
   PQCC compiler generator.  "An Overview of the Production
   Quality Compiler- Compiler Projects", B.W. Leverett et al,
   IEEE Computer 13(8): 38-49 (Aug 1980).  (See LG).