For years, O'Reilly has supplied digital files to Bookshare, a non-profit that provides accessible reading material to the print disabled. For qualifying readers, books are made available worldwide.
Although the DRM-free EPUB files in their ebook bundles are compatible with many reading systems for print disabled customers, many readers prefer the DAISY format that Bookshare provides, and either don't qualify for access via Bookshare, or would prefer to pay for the ebooks. Through a collaboration with Bookshare, O'Reilly has started making DAISY files available within their ebook bundles on oreilly.com for more than 800 titles. If you've already bought an oreilly.com ebook, you can find the DAISY files on your account page at https://members.oreilly.com or http://oreilly.com/e on a mobile device.
"Our mission at O'Reilly is to change the world by spreading the knowledge of innovators, and making our books available in accessible DAISY format helps us accomplish that mission."
There's more details on the DAISY format from the DAISY Consortium, including a list of software and hardware reading systems.