WSJT is a computer program for VHF/UHF communication using state of the art digital techniques.
It can decode fraction-of-a-second signals reflected from ionized meteor trails,
as well as steady signals more than 10 dB weaker than those required for conventional CW.
One of its operating modes, JT65, is particularly optimized for amateur EME (Earth-Moon-Earth) communications.
WSJT is open source software and is licensed under the GNU General Public License.
It has an active development group: for details see http://developer.berlios.de/projects/wsjt