''In addition, products should demonstrate the ability to work effectively with assistive and adaptive technologies.''
Moodle's interface is designed with WAI (W3C), SENDA (UK) and Section 508 (US) web-accessibility requirements in view, and core functionality is accessible via a text based browser.
Products should be input device independent e.g. can be operated by keyboard or mouse.Higher marks will be awarded to entries that meet this criterion.
Moodle is fully accessible via the keyboard only. Whilst much Moodle content and activities are accessible using a mouse only, a screen keyboard would be necessary for some functionality.
''Products should provide text equivalents for any video and multimedia presentations.''
Moodle does not include and video or multimedia presentations as installed, however such presentations can readily be included as content, and alternative, text-only, formats can be provided in parallel.
'' Products should include a visual focus indicator so users can anticipate the effects of keystrokes they type. This may indicate the focus location by moving the system caret. The caret is normally the blinking vertical bar that the user sees when editing text, but it can be placed anywhere on the screen, made any shape or size, and even made invisible.''
Such functionality is provided by through a standard, browser interface.
'' Products should support accessibility features such as: sticky keys; screen flashes when a sound is used in an application; high contrast; and mouse keys. Or alternatively, products should support universal access to the keyboard or mouse and trackpad.''
Such functionality is provided through a standard browser interface, with design in keeping with web accessibility guidelines. User themes can provide high contrast display if required.
''Products should include volume control and a visual cue for any audio alerts, where applicable.''
Whilst Moodle does not require sound, it supports the delivery of mp3 audio files with visual cues, standard operating system volume controls can be used.
It is highly desirable that products incorporate the above accessibility functions, or alternatively interconnect with and inherit, those functions of the operating system.
Moodle's interface has been written with web accessibility guidance in mind, and accessibility functions provided by the browser or operating system should be available. Furthermore, Moodle is available in, at present, 43 languages, making the system more readily accessible for those for whom English is not their first language, or for those using it to study MFL.
Great explanations, Miles! 
In the absence of our accessibility expert, I'll just add a little more:
Moodle's markup is well-structured and designed to be easily styled with CSS. This allows for the creation of themes at both site and course level. These themes may be tailored to the needs to specific user groups, for example high contrast or using fonts that dyslexics find easier to read.
An example of a theme that could aid accessibility would be the two-column layout theme "Kubrick". This has been designed in such a way that the main content appears before side blocks. This is of benefit to users who would work through the page in a linear fashion, for example a user listening to the page being read by a screen reader or someone navigating by keyboard using the tab key.
