isetlw.ini is a configuration file read by isetlw when the program starts. It contains settings for many of the options in the Options menu. If you change an option such as the font, isetlw will try to update the ini file when you exit the program. If the ini file is read-only or doesn't exist, no error will be displayed but obviously the changed option won't be saved.
Here is a sample isetlw.ini file:
[FONT]Example stl file for setting up graphics:
!echo offThe above stl file contains three isetl directives (directives start with a !) to turn off echo of included commands, allocate 30,000,000 bytes of working memory, and include all the commands in the file named donplot.stl. Note that donplot.stl includes several stl files and defines several functions, one of which is the plot function.
There are several isetl.stl files in common use that are specifically oriented toward calculus, abstract algebra, finite math, discrete math, etc.