I've just released version 3.0.2 of Dasher, which can be downloaded from

http://www.inference.phy.cam.ac.uk/dasher/Download.html 

This version should fix the bugs related to zooming at the top and
bottom of the canvas, and also introduces a keyboard control method
using the up, down and left cursor keys. This is intended for people
using switch input, but may be useful for other purposes.

Unix users have a new GTK2 interface, which will be compiled
automatically if GTKMM is unavailable or if the --with-gtk2 option is
passed to ./configure. There's an RPM of the GTK2 version, which should
make life easier for people who've had problems satisfying GTKMM
dependencies in the past.

Developers should note the introduction of a (mostly) C layer that
interfaces between the interface and the C++ core. At the moment this
still contains some vestigal C++ code, but in future it should be
possible to write Dasher interface code in C rather than C++ if desired.
Thanks to Phil Cowens for contributing this code.

-- 
Matthew Garrett 

Dasher is listed as a Debian unstable package