A notable example of this was the so-called "BSD Games", a collection of interactive fiction and other text-mode titles.[1] The free software and open source methodologies which spawned the development of the operating system in general also spawned the creation of various early free games. Popular early titles included NetHack, Netrek, XBill, XEvil, xbattle, Xconq and XPilot. As the operating system itself grew and expanded, the amount of free and open-source games also increased in scale and complexity.[citation needed]