It seems that every other device is now getting a jailbreak tool - the latest one to get the treatment is the Windows Phone 7. The tool is called ChevronWP7 and allows you to develop and install a Windows Phone 7 application on any phone. It also allows the user to bypass Microsoft’s approval process.
Official Windows 7 developers have to pay a fee of $99 to unlock their phones and allow deployment of custom software without using the Marketplace. ChevronWP7 allows users to do the exact same thing, but without the $99 price tag.
The developers of ChevronWP7 have said that they had two main objectives; one was to enable homebrew without paying Microsoft the $99, and the other was to open up development to everyone - including the residents who are currently ineligible for Marketplace accounts.
The tool has raised piracy concerns because it allows the user to load custom applications without using the Marketplace. The tool's creators insist that they were not in favor of piracy and simply wanted to allow homebrew development on the users’ phones.