Old warfare still kills and injures
Various militaries used the software of their day for such things as directing where bombs might be intended to be dropped, where mother bombs might disperse bomblets or small land mines, where ships might rendezvous, and much more. They archived data for software that ran on equipment where no one publicly has any of the old equipment and the data is in effect in limbo, if maintained at all. Yet for purposes of making land safe for the inhabitants, or for finding the odd old wreck, perhaps with human remains, this kind of tech needs to preserved, too. The problem is, of course, that a lot of the "work" done reflects very poorly on the reputations of the governments engaged in overseas warfare at the time. E.g.,
Addressing Unexploded Ordnance
Ordnance Dropped Estimated Percentage of Ordnance that Did Not Explode Casualties
(Injuries and Fatalities) Land Contaminated by UXO and Cluster Munitions
Cambodia 2.7 million tons, including 26 million cluster bomblets 25% 64,931 people 176 sq miles
Laos Over 2.1 million tons 33% 25,000 people Surveys confirm at least 3,270 square miles, with estimates much higher
Vietnam 8 million tons 10% Over 100,000 people 23,670 square miles
https://www.stimson.org/2021/ramp-up-u-s-engagement-with-war-legacies-in-southeast-asia/