TIP: EverySpec.com
Everyone knows about EverySpec.com, right? While it doesn’t have every spec, it sure has a lot of them. You won’t find illegal copies of the must-purchase ISO, CISPR, ANSI, etc. standards here. But you will find many of the publicly available ones. For me, being able to quickly and easily find MIL-STD and NASA standards has made this a go-to resource. Not only that, but the page for each standard has a nicely organized table where you can see not only the current revision of a document, but links to download each previous revision. That can be a real life-saver when you’re dealing with legacy systems and heritage hardware.