Dasher is an input method and computer accessibility tool which enables users to compose text without using a keyboard, by entering text on a screen with a pointing device such as a mouse, touch screen, or mice operated by the foot or head.

[2][3] Dasher is free and open-source software, subject to the requirements of the GNU General Public License (GPL), version 2.

Dasher is available for operating systems with GTK+ support, i.e. Linux, BSDs and other Unix-like including macOS, Microsoft Windows, Pocket PC, iOS and Android.

[7] For whatever the writer intends to write, they select a letter from ones displayed on a screen by using a pointer, whereupon the system uses a probabilistic predictive model to anticipate the likely character combinations for the next piece of text, and accord these higher priority by displaying them more prominently than less likely letter combinations.

The system learns from experience which letter combinations are the most popular, and changes its display protocol over time to reflect this.