[Rakesh Racky]

What's the difference between XAP and APPX app file format wp8.1 not supported XAP files

[anon(7900571)]

xap will be for windows phone 8 or windows phone 7 devices with old API and APPX or whatever the new file format is called will be only available for windows phone 8.1 devices since Microsoft will introduce many new API for developers ; another change is=they will merge windows phone 8 apps with windows 8 apps ; just like apple did for iPhone and iPad ; developers will have option to create apps for both windows phone 8.1 and windows 8.1.

[Naren Parker]

I think the .appx handles updates better than .xap. This was what I was wishing for when WP Blue was in development. Updates to app now hopefully wouldn't need to download the whole app but instead only the updated component of the app. This would greatly reduce data charges when infact the update could only be a few bug fixes or a new language support. Makes a huge difference when updating heavy games.