If you never heard of SPI, it refers to the Single Page Interface paradigm. This means that your 300 page website can be developed using the SPI so that it is a single page, no reloading, with no loss of typical website features such as SEO, bookmarks, etc.
ItsNat, an open source, Java AJAX component-based web framework, is designed for the creation of SPI websites. The Single Page Interface Manifesto was published to show developers how SPI can become real in websites. As an example, the company’s website was changed to SPI using the same look and feel, SEO, bookmarking and visit counters.
There have already been tutorials published that show how you create an SPI website using ItsNat. The tutorial includes a demo which showcases some of the SPI features, such as a simulated Back and Forward button which works. Time to move on to a large, real world site. The author cloned a large Spanish retailer using techniques similar to those in the tutorial listed above and created his own demo. It works in browsers that have disabled JavaScript, it’s SEO friendly, the navigation works without reloading, back/forward works with no reloading, the layout is the same as the original–in short this demo is very impressive!