I remember at some point there was a popular theory that if you add an "X" to a name, it appears more modern to the customer. So Microsoft started to brand diff

I remember at some point there was a popular theory that if you add an "X" to a name, it appears more modern to the customer. So Microsoft started to brand different technologies in this way. The data exchange mechanism became "ActiveX". Their abstraction layer for graphics cards became "DirectX".