Ask HN: What is the most impactful thing you've built?
Bit late to post, though the most impact for me was coding a Y2K bios/rtc tester. It was released as freeware and went global and also generated income for ppl testing PC's for y2k compliance. China had it as an official download on their gov website.The tester took around 3-mths to get to the production verion and used Turbo Pascal with inline assembly, C and quickbasic for the reports.The y2k was a big issue in the day and glad the tester played a small part in ensuring a smooth transition.