Debate around the advantages and disadvantages of commercial off-the-shelf (COTS) software versus one-of-a-kind, fully customised software has raged, there is a third, lesser-known, option: platform software. Think of the three software alternatives on a spectrum of development, with COTS on the left, custom-built software on the right, and the platform alternative somewhere in the middle. There are clear differences between them, with each having its own set of pros and cons. Here are five factors to consider when deciding between COTS, platform or custom-built Software.