The Collaborative International Dictionary of English v.0.48:

Jacal \Ja*cal"\ (h[aum]*k[aum]l"; 239), n. [Amer. Sp., fr. Mex.
   xacalli.]
   In Mexico and the southwestern United States, a kind of
   plastered house or hut, usually made by planting poles or
   timber in the ground, filling in between them with screen
   work or wickerwork, and daubing one or both sides with mud or
   adobe mortar; also, this method of construction.
   [Webster 1913 Suppl.]

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

JAffer's Canonical ALgebra
JACAL

    (JACAL) A symbolic mathematics program,
   most of which was written in Scheme by Aubrey Jaffer.

   (http://swissnet.ai.mit.edu/~jaffer/JACAL.html).

   (1999-06-27)