This latest Facebook desktop client is by Microsoft and is based on Silverlight.
There are many applications that lets you use Facebook on desktop, but not all give you a nice interface with almost all the Facebook features built in it.
Photo Uploader for Facebook is actually an Adobe AIR Facebook desktop application that lets you upload photos by simply drag-and-drop, but along with features to make a complete desktop app.
Facebook is now the most popular social network with over 300 million active members. Even being this big, Facebook has no official application for desktop to manage their updates and account without opening the Facebook website.
I have managed to compile a list of (almost) all the desktop applications available for Facebook, and I’m sure people like me who are very active on Facebook would love to try them out.