Previously, Facebook had two mobile websites: touch.facebook.com for touchscreens and m.facebook.com for other mobiles.
Facebook says there were two major problems with this approach:
● Every time we launched a new feature, we had to build it multiple times across different code bases: once for facebook.com, then again for m.facebook.com, touch.facebook.com, and in native applications as well. Honestly, we werent very good at doing this, so certain features were missing on different devices.
Facebook has now unified the sites on m.facebook.com using a single framework which will display an interface based on the device's capabilities.
Every device uses the same framework. This way we can move even faster and build new features just once for every mobile device. It also means that everyone can access the same features, whether writing messages or checking into Places. There will no longer be a difference between m.facebook.com and touch.facebook.com, well automatically serve you the best version of the site for your device.
The new site is powered by a UI framework based on XHP, Javelin, and WURFL, a detailed database mapping user agents to device capabilities. You can learn more at the link below...
Read More [via Samar]