Mathematica has over a thousand options that allow full control over every aspect of its interface. These options can be set interactively from menus, defined in stylesheets, or manipulated programmatically using
Mathematica's symbolic programming capabilities.
— set global preferences such as syntax coloring
— all notebook and interface options, settable at various levels
— pick a stylesheet for a notebook
— edit a complete or cascading stylesheet
— localize everything by notebook, cell, ...
— specify the local or remote kernel to use for evaluation
Options,
SetOptions — programmatically find and set all notebook options
