Adobe Digital Editions is an ebook reader software program from Adobe Systems built initially (1.x version) using Adobe Flash. It is used for acquiring, managing and reading eBooks, digital newspapers, and other digital publications. The software supports PDF, XHTML (through the nonproprietary .EPUB file type specification), and Flash-based content. It implements a proprietary scheme of Digital Rights Management which, since the version 1.5 release in May 2008, allows document sharing between multiple computers and user authentication through an Adobe ID. Adobe Digital Editions is a successor to Adobe eBook Reader.
Windows and OS X versions of Adobe Digital Editions were released on June 19, 2007. Previous versions of the software required version 9.0 of Adobe Flash Player. Starting with version 2.0, however, which relies on .Net 3.5 on Windows, Flash Player is no longer supported. Adobe initiated development of a Linux version of Adobe Digital Editions in 2007, however this has not had any beta release or any formal updates.
Digital rights management 
Adobe Digital Editions uses the proprietary ADEPT (Adobe Digital Experience Protection Technology) digital rights management scheme, which is also implemented on some e-book readers, including iPads and many Android devices, but not Kindle. The software locks content to up to six machines and allows the user to view the content on each of them. Barnes & Noble (B&N) ebooks are protected with a variant of ADEPT.
In March 2009, the author of the reverse engineering blog i♥cabbages announced that they had broken the scheme.
Adobe Digital Editions by default on Windows machines stores .pdf files of the documents in My Documents/My Digital Editions, where they can be copied and handled like other files, but they cannot be opened except with Adobe Digital Editions. Adobe's website has virtually no information on Adept except on its trademark page and a statement that OverDrive is compatible.
See also 
External links