Over at Ebby’s blog there is a great article on how to make your xbap (WPF windows platform application) talk to your web page and send data back and forth. Note this is just for people using Windows XBAPs, which are sort of like Silverlight XAP files but for Windows platform applications only (in other words these apps require you to be running Windows on the machine you are accessing them on for them to work).. Why would you use an XBAP ? if you have a Windows Program you have made and you don’t wish to require people to run an installation program..