Adobe Reader XI was the last version to use the “Reader” branding before the company transitioned to “Adobe Acrobat Reader DC” (Document Cloud) in 2015. It was also the final version released under the traditional perpetual license model (one-time purchase for the professional Acrobat XI suite, with Reader remaining free). Version 11 arrived at a time when mobile computing was exploding (Windows 8 and early iPads were gaining traction), and PDFs were the de facto standard for immutable document exchange.