NVDA (Non-Visual Desktop Access) is a popular free screen reader used by many in the home and in education. Whilst not being suitable for the corporate environment it has many features in common with the more customizable Jaws.

More information is available at the about NVDA page.

Excerpt from about NVDA page

Providing feedback via synthetic speech and Braille, NVDA allows blind and vision impaired people to access and interact with the Windows operating system and many third-party applications.

Major highlights include:

• Support for popular applications including web browsers, email clients, internet chat programs and office suites
• Built in speech synthesizer supporting over 43 languages
• Automatic announcement of text under the mouse and optional audible indication of the mouse position
• Support for many refreshable Braille displays
• Translated into many languages
• Support for modern Windows Operating Systems including both 32- and 64-bit variants