WordCloud

WordCloud[{s₁,s₂,…}]

generates a word cloud graphic in which the s_i are sized according to their multiplicity in the list.

WordCloud[{w₁s₁,…}]

generates a word cloud in which the s_i are sized according to the weights w_i.

WordCloud[s₁w₁,…]

also generates a word cloud in which the s_i are sized according to the weights w_i.

WordCloud[{w₁,w₂,…}{s₁,s₂,…}]

also generates a word cloud in which the s_i are sized according to the weights w_i.

WordCloud[{{s₁,w₁},{s₂,w₂},…}]

also generates a word cloud in which the s_i are sized according to the weights w_i.

WordCloud[data,shape]

fits the word cloud into the region defined by shape.

Details and Options

Word clouds are also known as tag clouds and are often used to visualize popularity of phrases or words in a given context.
The s_i can be strings or any other expression. They are rendered in the word cloud however they would normally be displayed.
WordCloud returns a Graphics object where each object s_i is displayed with linear dimensions proportional to its weight.
WordCloud["string"] generates a word cloud of the words in "string".
Each of the s_i can be given a symbol wrapper, which affects its behavior or rendering:

	Annotation[s_i,label]	provide an annotation
	Button[s_i,action]	define an action to execute when clicked
	EventHandler[s_i,…]	define a general event handler
	Hyperlink[s_i,uri]	create a hyperlink
	PopupWindow[s_i,cont]	attach a popup window
	Rotate[s_i,θ_i]	rotate by θ_i radians
	StatusArea[s_i,label]	display in the status area when moused over
	Style[s_i,…]	show using the specified styles
	Tooltip[s_i,label]	attach an arbitrary tooltip

Data not given in the form above is taken to be missing and will be ignored.
The cloud shape mask can be given in the following forms:
image nonzero pixels of an Image object

graphics nonzero pixels of a rasterized Graphics object

region any 2D geometric RegionQ object
WordCloud has the same options as Graphics, with the following additions and changes:

Background	Transparent	background color to use
ColorFunction	Automatic	color based on weight and word
ColorFunctionScaling	True	whether to scale weight argument of ColorFunction
FontFamily	"Helvetica"	the family of font to use
FontSize	Automatic	range of font sizes
FontTracking	"Plain"	the compression of characters
FontWeight	Plain	the weight of characters to use
IgnoreCase	True	whether to ignore case when computing multiplicities
MaxItems	Automatic	maximum number of words to show
PlotRange	Automatic	range of values to include
PlotTheme	$PlotTheme	overall theme for the plot
PreprocessingRules	Automatic	how to pre-process specific elements
RandomSeeding	Automatic	specify the random seed
ScalingFunctions	Identity	scaling of the weights
WordOrientation	"Horizontal"	orientation of the words to use
WordSelectionFunction	Automatic	function to determine whether to include a word
WordSpacings	Automatic	space to add around each word

With ImageSizeAutomatic, the actual font sizes used are specified by FontSize, and the computed ImageSize will vary to fit the word cloud.
With ImageSize fully specified, rescaled font sizes are used so that the resulting word cloud will fit in the specified image size.
ScalingFunctions is applied to weights w_i, with settings:
Identity,None no scaling function (default)

Log logarithmic scaling

power scaling

f use the scaling function f
FontSize can be used to control font sizes from scaled weights with settings:

	Automatic	automatically computed min and max size
	max	automatically computed min size
	{min,max}	explicit min and max size
	g	explicit mapping g between scaled weights and font size

PreprocessingRules can be used to specify how to transform individual words. If the weights are not specified, the preprocessing happens before counting.
Using WordSelectionFunction->f, the function f takes the words as the first argument. Optionally, the corresponding weight can be given to f as the second argument:
#Word or #1 the word s_i

#Weight or #2 the weight w_i