Back in 1995 it was, to my knowledge, the only OS capable of sharing CD-ROM's on the network. Even MS-DOS and Windows 3.11 machines could access it.

It was also capable of sharing Mainframe printers using a real null-printer-driver, which was not possible on Windows NT3.51 or NT4.0. Windows always messed with the Mainframe codes that it could not understand.

It was also easy to set up OS/2 as a gateway between different network hardware and protocols (Token Ring to Ethernet, or NetBios to IPX/SPX, ...)

It had REXX!