I’ve often mentioned that one of the key, foundational strengths of the IBM mainframe is its support for “old” program code for as long as that code still has business value to the organization that runs it. With rare exceptions, you don’t have to throw away your perfectly useful, well-functioning, well-integrated, costly-to-create (or recreate) code just because IBM or some other vendor decides the technology ought to be obsolete for whatever parochial reasons they have. That 1964 hallmark commitment to backward compatibility is practically sacred because that’s what makes sense for business. That doesn’t mean you should or must run every program written decades ago, but it means you can when it makes sense. Good stuff — though often misunderstood and occasionally abused (in business terms).
In that spirit, let’s see if you, our loyal readers, can come up with the best answers to the following questions about the “oldest” software. “Oldest” has many possible definitions. See if you can identify the following pieces of software and their years (or approximate years) they were born (or last modified):
1. Oldest program of any kind in any medium that’s still running today.
2. Oldest program still running on an electromechanical computer.
3. Oldest program still running on z/OS. (Hint: Likely an in-house application, and likely born pre-System/360, i.e. before 1965.)
4. Oldest program included within z/OS 2.1. (That is, the program module within z/OS unmodified for the longest period of time.)
5. Oldest vendor program for z/OS still marketed. (In this case “oldest” will be somewhat arbitrarily defined as longest period of time without a change in either the version or release number, or vendor equivalent. “Marketed” is tricky, but let’s set some boundaries: the program must be listed on a vendor’s Web site, the vendor must still be answering their phone, and a non-absurd price quotation is obtainable.)
6. Oldest IBM program for z/OS still marketed. (Same “oldest” and “marketed” as #5.)
7. Oldest vendor program for z/OS still supported. (Same “oldest” as #5. May or may not be the same answer as #5.)
8. Oldest IBM program for z/OS still supported. (Same “oldest” as #5. May or may not be the same answer as #6.)
9. As a bonus, the oldest model mainframe hardware still in productive end-user service (i.e. not in a museum or equivalent).
The floor is open, and nominations are now being accepted in the comments. Good luck!