Imagine how different the tech industry might have been had Gary Kildall accepted IBM's offer, back in 1980, to license his computer operating system for a top-secret project. CP/M would have been the OS that shipped with the original IBM PC, and the world might never have heard the name of Kildall's competitor, who eventually accepted the contract: a Mr. Bill Gates.

For all the amazing advances that the computing industry has brought us over the years, some of its most pivotal moments are memorable for all the wrong reasons. Not every idea can be a winner, and not even Microsoft can avoid every misstep. But as they say, those who forget history are doomed to repeat it -- and then again, others just keep screwing up. In the interest of schadenfreude, then, here is a look back at the last 20 years' worth of blunders, fumbles, also-rans, and downright disasters that you may have forgotten about -- or wish you could.

Top tech flops Nos. 21-25: PS/2, VR, compression wars, ...
Top tech flops Nos. 16-20: Copland, Gnu Hurd, Oracle Raw Iron, ...
Top tech flops Nos. 11-15: Palm OS Cobalt, Netscape 6, search engines, ...
Top tech flops Nos. 6-10: Itanium, Mac clones, e-currency, ...
Top tech flops Nos. 1-5: DRM, paperless office, iPod imitators, ...