retrobrowse is an open source software maintained by Tsubasa Kato at Inspire Search that allows old devices such as PDAs to view modern sites. It acts as a proxy + HTML5 to IE3 browser converter, so it strips off HTML5 related tags.
It's useful to view sites that are coded with HTML5, and all you want is the text and main images.
It will be useful to reduce your packet size, therefore enabling faster access to web content on the go when you have low bandwidth.