NonVisual Desktop Access (NVDA) is a free and open source screen reader for the Microsoft Windows operating system.
"NonVisual Desktop Access" (NVDA) is a free, open source, portable screen reader for Microsoft Windows. The project was started by Michael Curran in 2006. It currently works exclusively with accessibility APIs such as Microsoft Active Accessibility, IAccessible2 and the Java Access Bridge, rather than using specialized video drivers to 'intercept' and interpret visual information. It is licensed under the GNU General Public License.
NVDA uses eSpeak as its integrated speech synthesizer, and also supports SAPI synthesizers. Output to Braille displays is supported officially from Version 0.6p3 onwards.
NVDA software enables blind and vision impaired people to use a computer by communicating what is on the screen using a synthetic voice or braille.
NVDA (NonVisual Desktop Access) is the only screen reader for Microsoft Windows that is totally free, yet fully functional and portable. You can download it to your PC, or to portable media such as a USB stick which you can use with any computer at school, work – anywhere!
It was created by NV Access founders Michael Curran and James Teh – blind computer programmers who believe passionately in universal access to computers. NVDA is free. It’s been downloaded 70,000+ times, in 43 languages.
Source: NV Access