Flash had its own constraints that kept web applications from meeting the needs of users. For instance, Flash requires a special extension to be added to each browser, and the extension requires frequent updates. Flash applications were also self-contained are also generally divorced from all the other content on the web page and thus their contents are not indexed by search engines.
—Marjee Chmiel, MA, PhD
Perfetti, Christine, and Jared M. Spool. “Macromedia Flash: A New Hope for Web Applications.” UIE. com. User Interface Engineering, 2002. Web. 5 Aug. 2013.
Yule, Daniel, and Jamie Blustein. “Of Hoverboards and Hypertext.” Design, User Experience, and Usability. Design Philosophy, Methods, and Tools. Berlin: Springer, 2013. Print.