Section 508 of the Rehabilitation Act, as amended in 1998, requires federal agencies to ensure accessibility of software (and other electronic and information technology) that it develops, procures, maintains, or uses. The Access Board published a set of standards to support Section 508. The final standards document, Electronic and Information Technology Accessibility Standards, includes a "Software Applications and Operating Systems" section. There are twelve standards in this section, and each is explained in greater detail in the Access Board's Guide to the Standards.
The Section 508 standards and supporting documents are an excellent reference tool, even for noncovered entities. For more technical information, however, one excellent resource is the IBM Software Accessibility Checklist. This checklist includes twenty checkpoints in seven categories, and each of the checkpoints links to specific techniques documents.
In addition, each of the major operating systems vendors has developed its own documentation to support developers in creating accessible software for its platform. For example, Microsoft provides a variety of technical reference materials on the Microsoft Developers Network (MSDN) User Interface Accessibility page, Apple provides Accessibility Documentation in its Developer Library, and Sun provides a variety of resources through its Sun Microsystems Accessibility Program, including information on developing accessible applications using Java. For Linux Developers, the GNOME Accessibility Project provides a suite of software services and support to assist in making accessible applications for the GNOME desktop system.
Developers can also learn by sampling other software that was developed in accordance with accessibility principles. One example of an accessible software application is Digital Frog's The Digital Field Trip to The Rainforest.
For additional background, see What makes electronic and information technology inaccessible to people with disabilities?.