Free text to speech software

Free text-to-speech
Some of these listed sell versions with high quality voices.
Natural Reader - http://www.naturalreaders.com/
Readplease - http://www.readplease.com/
SayzMe - http://www.datafurnace.net.au/sayzme/
Readpal - http://www.readpal.com/one/screenreader.htm
Helpread - http://helpread.net/
Powertalk - http://fullmeasure.co.uk/powertalk/
Yread - http://spacejock.m6.net/Downloads.html