The default initialization file init.m tries to initialize the correct graphics system for your session, but may not always do what you want. When using Mathematica under X, each graphic output will appear in its own window. Upon exiting the editor, the contents of the buffer will be read into Mathematica as input. You may prepare a file with lines of Mathematica input, then run it through Mathematica to produce output, which can be directed to another file. Where command is a Unix command, expression is a Mathematica expression, and graphics is a Mathematica expression evaluating to graphics output.
Users can order documentation by issuing the pubware command and following instructions.