A lot of organizations think they'd be happier with Web applications that correspond to desktop (or "client-server") applications they already have. Sometimes, they're right. Often, they analyze with too much effort, and unsatisfying results, the technical effort of the transition. "Webification" is both easier and harder than they know.
Just to make something work through the Web is surprisingly often a fifteen-minute job, through the magic of VNC and allied "remoting" technologies. "Take Your Desktop Application to the Web in 15 minutes" illustrates the happy possibilities, some of which Vasudev Ram further paraphrases in "Webify any desktop app quickly ...". The downsides:
Remoting is far from the the only possibility, though. Specific GUI toolkits can be "floated" to the Web in various ways:
[Provide live examples.]
[Explain multiple roles of HTML5.]