SM is an interactive plotting program written by Robert Lupton and Patricia Monger. SM has its own command language. It is possible to write macros. The plot is executed as a sequence of commands. The SM code is particularly popular in the astrophysics

Astrophysics

Astrophysics is the branch of astronomy that deals with the physics of the universe, including the physical properties of celestial objects, as well as their interactions and behavior...

 community. SM is based on the Mongo

Mongo (graphics program)

Mongo is a graphics program written in FORTRAN by John L. Tonry. It is copyrighted software, but it is free for use and distribution, under the terms of the GNU General Public License....

 plotting package developed in the early 1980s by John L. Tonry. Compared to Mongo, SM has a greatly enhanced command language, which includes algebraic manipulation of data vectors.