The only OS that IBM produces is called AIX. AIX is a flavor of Unix. http://en.wikipedia.org/wiki/AIX_operating_system
os for IBM
The operating systems which were developed by Apple and IBM are Mac OS and OS/2. However, OS/2 is no longer being used as IBM is no longer in the operating system market. Microsoft now makes operating systems which work on IBM computers.
Bill Gates never worked for IBM. He was the founder of Microsoft. But, Mircrosoft and IBM licensed MS-DOS for IBM's new IBM PC-AT. They then began working to develop, OS/2 a more advanced operating system. But Microsoft had different plans and IBM finished OS/2 by itself.
Microsoft worked with IBM to develop DOS and I believe OS/2 as well.
os/2
Apple OS X Microsoft Windows Unix Linux VAX/VMS OS4000 IBM System/360 DOS IBM OS/2 RISK OS Free RTOS OS 2200 Exec 8 (There are lots more)
Probably the IBM 7090 in 1958 running IBSYS. IBSYS was originally developed on the IBM 709, but when it was introduced in 1956 of course it had no OS at all. Programs were all loaded and run manually.
MS-DOS
The "creator" of AIX is the IBM corporation. Since it is a team effort there is no one individual responsible for the OS.
OS/390, OS/400 are still alive and they rock!
DOS {disk operating system }
OS/2