A software developer in the 1990s built a real-time GPS moving map display on a 25MHz 486-SX processor with minimal floating-point math, using the Hipparchus library's integer-based algorithms. The system was significantly faster than consumer GPS devices that emerged years later, but the developer lost access to the project when the client faced financial difficulties.
Internet guestbooks were simple HTML forms on personal websites where visitors could leave messages, borrowing the concept of physical visitor logs. Popular in the 1990s through early 2000s, especially on platforms like GeoCities, they were typically hosted by free providers like Lpage and Dreambook. Unlike modern comments, guestbooks required more effort and offered no algorithmic visibility, creating a more personal connection between strangers on the early web.