Maplex for ArcGIS adds some tools to the Labeling toolbar.

The tools on the Labeling toolbar are:

Abbreviation Dictionaries—Lets you specify how words in labels are abbreviated.

Use Maplex Label Engine—Lets you switch the Maplex Label Engine on or off for the active data frame.

Options—Lets you set basic and advanced Maplex Label Engine options for the active data frame.

Label Manager button—Lets you control all of the label classes in your map from a single dialog box.

Label Priority Ranking button—Lets you control the order in which label classes are placed. More of the labels from higher priority classes are usually placed.

Label Weight Ranking button—Lets you control the relative importance of features as barriers to label placement.

Lock Labels button—Locks the labels displayed in the current extent. This allows you to navigate around a map without having to wait for the label placements to be recalculated each time you pan or zoom.

View Unplaced Labels button—Shows the labels that could not be placed in a different color (the default color is red).

Placement Quality dropdown list—“Fast” allows you to place labels quickly using a simple calculation. “Best” uses a more complex calculation and takes longer.