The Wolfram Language 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 the Wolfram Language's symbolic programming capabilities.
Preferences — set global preferences such as syntax coloring
Option Inspector — all notebook and interface options, settable at various levels
Notebook's Kernel — specify the local or remote kernel to use for evaluation