The MultiAutoComplete control allows user to pick multiple items from a list that contains either custom objects or simple strings. Once you enter some text in the control field, MultiAutoComplete starts searching for items that match the entered string and displays a list of possible results. After selecting one of the items from the list, it shows up in the control field.
The control allows you to select multiple items in the similar manner. It also provides an option to set a limit to number of items that can be selected.