In Windows Mobile 6.5.3 and below, carriers and OEMs could preload devices with any applications they desired. This often left devices full of java-based trialware and other apps that would clog the device’s storage memory and hog system resources (take a look at this screenshot from the AT&T Pure. Circled are AT&T apps). In Windows Phone 7 series, as we mentioned in our post about the system architecture, Microsoft has made it much more difficult for carriers and OEMs to add trialwarew. More specifically:

Regarding preloaded applications by OEM/MO: Requirements are much more strict in this regard now due to frequent end-user complaints about “slow, laggy, etc” Stock ROMs. I know every one of you reading this knows what I mean Preloaded App Requirements (which will be distributed as .xap) as follows:

- Maximum of 6 preloaded applications on the device, not to exceed 60MB

- All preloaded apps must pass Marketplace submission process (some extended APIs are available to OEM/MO so the process is slightly relaxed in that regard)

- The application(s) and all future updates must be free of charge.

- The apps must launch without dependency on network availability.

- The apps must persist through a “hard reset”.

- The apps must be updatable and revocable (!!!!) through the Marketplace.

- The apps must notify the user at first launch of any capabilities to be utilized and get user consent (to access compass, accelerometer, network, etc.)

While this may seem a bit restrictive, it’s a good thing for the consumer.

(via: XDA)