TheirEditor is a program that allows users to select and edit text. You can do this by clicking it or dragging over the text.
A text selection can be very discontinuous. That is, it can consist of any combination of single characters, words or groups of words which can be freely scattered all over the document. As in a normal editor, selected text can be copied or deleted. It can also be sent to a list.
It operates in three granularity modes: A character at a time, a "word" at a time, or a line at a time. It operates in three directionality modes: Normal (no directionality), to the beginning of the line, and to end of the line. With some tools, Shift+dragging will perform a "local undo".