The Free On-line Dictionary of Computing (30 December 2018):

Internal Translator

    (IT) An early compiler for
   mathematics developed by A.J. Perlis et al at Carnegie Tech
   ca 1957.  IT was originally written for the Burroughs 205,
   then the IBM 650.

   IT was the forerunner of RUNCIBLE, GATE, CORRELATE and GAT.
   IT source code was converted to PIT, thence to SPIT.

   IT-2 produced machine language directly, IT-3 developed at
   Carnegie added double-precision floating-point.

   [Sammet 1969, pp. 139-141].

   [CACM 1(5):22 1958].

   (1994-11-30)