I've come across a few questions in the forums about version numbers in the Marketplace. Having answered questions around this several times I thought it was time to do a blog posting.
Some users have installed applications from the Windows Marketplace for Mobile and noticed that when they check on the version number for the application (usually through the menu sequence Help->About) they see a version number that doesn't match the version number as listed in the Marketplace. Some users have thought this was an indication that the wrong version of the application had been sent to them.
The confustion comes from there many times being no relationship between the version number listed in help->about and the version number reported by the Marketplace. The version number reported by the application uses the format <major version>.<minor version>.<build>.<revision> while the marketplace uses <major version>.<minor version>. As a software developer I could publish an application and have it's version number as 18.104.22.168 in help-> about and 1.0 in the Marketplace. But if I make a minor update to it and update help->about to display 22.214.171.124 it mail display 1.1 in the marketplace. For my next update it may be 126.96.36.199 but 1.2 in the marketplace. See how these numbers are begining to diverge?
One of the applications in question is the Bing application. Bing comes preinstalled on many devices and there have been users that have thought that that version preinstalled on their device was preventing the installation on the lates version. As a test I took a device that had no version of Bing on it and connected to the Marketplace. When I found Bing in the Marketplace it shows that it is on version 6.
I downloaded and installed the version that the Marketplace reports to be version 6.0. Going through the menu sequence Help->About we see that the Marketplace 6.0 labeling is for verxion xxx of this app.