MacromediaFlash, now owned by AdobeSystemsInc, is a well known tool to create graphically rich (they use the word "engaging") presentations for use on the web.
Adobe acquisition announcement can be seen at http://www.adobe.com/aboutadobe/pressroom/pressreleases/pdfs/200504/041805AdobeAcquiresMacromedia.pdf
See http://www.macromedia.com/software/flash/
Some people feel that Flash animations on a web site typically add little value for the visitor. See WhatsWrongWithFlash for details.
See also FreeSoftware for generating SWF files:
RichInternetApplication domain
MacromediaFlex is the development platform for AjaxWebApplications equivalent and it generates SWF files from XML.
The company is quick to point out that use of MacromediaFlash for RichInternetApplication would increase market penetration quickly, due to lack of WebBrowser compatibility concerns. See more at http://www.internetnews.com/dev-news/print.php/3527226
See also: ToggleYourFlash