pix \- Pascal interpreter and executor
is a `load and go' version of Pascal which combines
the functions of the interpreter code translator
to translate the program in the file
and, if there were no fatal errors during translation,
causes the resulting interpreter code
with the specified arguments.
A temporary file is used for the object code;
is neither created nor destroyed.
/usr/bin/pi Pascal translator
/usr/bin/px Pascal executor
/usr/lib/how_pix basic explanation
Berkeley Pascal User's Manual
For a basic explanation do
Susan L. Graham and William N. Joy