For many years, buying a software application or system meant that almost all of the development was done from scratch. That is to say, each act of development was unique or bespoke, just like the engineering done in the early years of the industrial revolution. Nowadays, less and less software is being developed in this way. Instead, software applications are available in shrink-wrapped boxes containing a CD-ROM or are downloadable from the internet. These are known as commercial, off-the-shelf software or COTS for short. The term product line is used to denote a set of related products that are sold by the same company. Software has also become a major component of mass-produced items, such as motor vehicles, televisions and mobile phones.