25 Years of IBM’s OS/2: The Strange Days and Surprising Afterlife of a Legendary Operating System | Techland | TIME.com

The excerpt below is from the third page of an extensive Time OS/2 profile

"Try though it might, IBM couldn’t force an unwilling world to use OS/2 as its primary operating system. But it also couldn’t extinguish demand for the operating system simply by declaring that it wasn’t going to sell and support it anymore, an announcement it made in 2005. In 2012, OS/2 is invisible to the naked eye, but it’s still out there, in more places than you’d think.
In New York City’s subway system, for instance, the travelers who gain entrance by swiping their Metrocard fare cards over five million times each weekday do so with the assistance of IBM’s theoretically defunct software. “While OS/2 is not running any visible part of the system, it does serve an essential purpose and there are hundreds of OS/2 computers in service,” says Neil Waldhauser, a consultant who helps New York City Transit and other clients keep their OS/2 applications running."

25 Years of IBM’s OS/2: The Strange Days and Surprising Afterlife of a Legendary Operating System | Techland | TIME.com