Read original post by Andreas Hammar at JayWay Blog
This blog post is part of a series about how Windows Phone 8.1 affects developers. The series is written in collaboration with Microsoft evangelist Peter Bryntesson, check out his blog here.
When it comes to packaging and distribution of apps – Xap is out, Appx is in. Appx is the package model used by the Windows Store and offers some additional features over xap.