Get the current value of an option for the front end:

Get the current value of an option for a notebook:

Get the current value of an option inherited by a Dynamic:

Get the current value of a suboption:

Get the current value of a specific rule within an option:

Get the current value of rules within rules within options:

Give a list of current values corresponding to several cell objects:

Use platform-specific controls font:

Use platform-specific panel font:

Style elements to look similar to a tooltip:

Detect whether the mouse cursor is over the content:

Get the absolute current position of the mouse on screen:

Get the scaled current position of the mouse on screen:

Get the mouse position inside a graphic:

Check whether the current notebook is selected:

Get the notebook file name:

Get the directory path of the current notebook:

Get the full path of the current notebook:

Get a list of all modifier keys being pressed:

Check whether a specific modifier key is being pressed:

Detect whether current cell is selected:

Get the box structure of the selection in this notebook:

Select parts of the expression below:

Detect whether current evaluation is inside Dynamic:

Detect whether current evaluation is synchronous:

Set the notebook background to be red for a second and then reset to original value:

Use Dynamic to set the notebook background:

Or set the window opacity: