What do you think is the greatest piece of software every written? That's probably not a question that comes up very often, but it is an interesting one to ponder. Personally, I wouldn't even know where to begin. Charles Babcock of InformationWeek, however, has put together an interesting piece which aims to answer the question. Good reading if you've got some time to spare.
"I've always been amazed at the Apollo spacecraft guidance system, built by the MIT Instrumentation Lab. In 1969, this software got Apollo 11 to the moon, detached the lunar module, landed it on the moon's surface, and brought three astronauts home. It had to function on the tiny amount of memory available in the onboard Raytheon computer--it carried 8 Kbytes, not enough for a printer driver these days. And there wouldn't be time to reboot in case of system failure when the craft made re-entry. It's just as well Windows wasn't available for the job."