NonVisual Desktop Access (NVDA) is a free and open-source, portable screen reader[1] for Microsoft Windows.

Towards the end of 2006, Curran named his project Nonvisual Desktop Access (NVDA) and released version 0.5 the following year.

To manage continued development of NVDA, Curran, along with James Teh, founded NV Access in 2007.

Also in 2013, NV Access introduced a restructured method of reviewing screen text, and introduced a facility to manage profiles for applications, as well as improving access to Microsoft Office and other office suites in 2014.

[17] Besides general Windows functionality, NVDA works with software such as Microsoft office applications, WordPad, Notepad, Windows Media Player, web browsers such as Mozilla Firefox, Google Chrome, Internet Explorer, and Microsoft Edge.

[17][19] NVDA is organized into various subsystems, including the core loop, add-ons manager, app modules, event handler and input and output handlers, along with modules to support accessibility APIs such as Microsoft Active Accessibility.

NVDA also provides facilities to handle events such as key presses, name changes and when an application gains or loses focus.

NVDA provides facilities to examine an application's object hierarchy and implement ways to enhance accessibility of a program.

It provides dedicated commands to move through object hierarchy within an application, as well as an interactive python console to perform focus manipulation, monitoring objects for events and test code for improving accessibility of an application to be packaged in an app module.