Earlier quoted context omitted.
Right, but look at history: MySpace died out (mostly), and was replaced, but by what? Facebook, another centralized, proprietary service. And then came Twitter, which was yet another centralized, proprietary service. When has an open, decentralized product or service ever supplanted a centralized, closed, proprietary one? Never, that I can think of. Linux never replaced Windows, not for the vast majority of users. It…
That's getting close to a "no true Scottsman argument." You go through the list, find every successful open source project, and try to explain why it doesn't count. Some of your examples are flat out wrong: Oracle was the big dominant proprietary player when Yahoo decided to risk going with MySQL (which was great, and I can't wait for MySQL to get replaced by Postgres). Now think how many websites are running on Word…
Wrong, I explain why in each case, they've completely changed the market, they didn't just come in and take over from a successful and dominant proprietary player.
>Oracle was the big dominant proprietary player when Yahoo decided to risk going with MySQL
No, they weren't. Oracle was never big in web databases. Ever heard of the LAMP stack? There was never a "LAOP" stack. Oracle was never used as part of a stack with Linux and Apache and Perl or PHP. Oracle was used in a bunch of big-iron systems back then (and still are), but they were never a serious player in small webservers. MySQL helped create that market.
This is something like claiming that Harley-Davidson took over part of the market owned by the Ford Model T truck.
>Now think how many websites are running on WordPress. It pains me to say it (because the code quality is so bad), but that's an example of successful open source project.
Which proprietary product did it out-compete? That's right, none. WordPress created a whole new market. It's just like all my other successful FOSS examples. It never successfully out-competed a dominant proprietary product.
>Git is up there too.
git is probably about the only FOSS product, now that you mention it, that's made any real inroads against proprietary products, and even here, not that much. It's used all over the place for FOSS development of course, but there was never a dominant proprietary product used for source control for FOSS development. BitKeeper was the closest to it, and that was only used for a single project AFAIK (the kernel), and using a special gratis license. FOSS development has always been done with FOSS VCSes: CVS, SVN, Mercurial, etc. Now, git has made some inroads against ClearCase and Perforce in corporate software development (as have all the other ones: SVN, CVS, Hg, etc.), but usually only for new projects. ClearCase has been very hard to dislodge in the companies where it's been standardized on (even though it's an absolutely abysmal version-control system that only succeeds in hindering progress).
>So if you define the category narrowly enough
I've already stated my requirement. Show me a good example of a FOSS product completely taking over for a highly successful and dominant proprietary one, instead of just creating a new market or expanding the market (while not displacing the proprietary product at all). I don't think you'll be able to come up with a single one.