Adobe Digital Editions and RMSDK were recently sold to Wipro Engineering: https://helpx.adobe.com/enterprise/kb/eol-faq-adobe-digital-...

Sold or outsourced?

> Wipro now manages and distributes any new updates, enhancements, bug fixes, and support requests directly

> Create your new ByteBooks ID using the same email address that you used for Adobe ID

Seems sold mostly.

'transitioned'