NextGrayCodeSubset[l, s] constructs the successor of s in the Gray code of set l.

NextLexicographicSubset[l, s] gives the lexicographic successor of subset s of set l.

RandomKSubset[l, k] gives a random subset of set l with exactly k elements.

RankSubset[l, s] gives the rank, in canonical order, of subset s of set l.

UnrankKSubset[m, k, l] gives the m\[Null]^th k-subset of set l, listed in lexicographic order.

Mathematica allows detailed control of the overall look and operation of notebook windows.

CellTags is an option for Cell that gives a list of tags to associate with a cell.

TooltipDelay is an option for objects such as Tooltip that specifies how long to delay after the mouse is over the object before displaying the tooltip.

WindowElements is a notebook option that specifies the elements to include in the window used to display the notebook on the screen.

As soon as you connect almost any kind of controller or input device to your computer, Mathematica will immediately let you use it to control Manipulate, 3D graphics, etc. ...