Modding
Modding is a slang expression for the act of modifying a piece of hardware or software to perform a function not intended or authorized by the original manufacturer.Some nations have laws prohibiting modding and accuse modders of attempting to overcome piracy-protection schemes. In the United States, the DMCA sets up stiff penalties for modding.
On the other side, some companies actively encouraging modding of their products. In cases such as Tivo and Google, there has been an informal agreement between the modders and the company in which the modders agree not to do anything that destroys the companies business model and the company agrees to support the modding community by providing technical specs and information.