How many OS are there at present and what are they?

In estimate, how many features of UNIX based OS are barely or never used, yet have frequent/permanent resource consumption?

• other releases apart from OS X, iOS, Linux, Android and Chrome OS. If possible, name some of them.

• Answer:

  I do not know about OS X and iOS. They are as optimal as OSes can get. Never found a useless bit. Coming to Linux, it is what you make of it. Distros can be cunts but if you know what you want and run a customized one (say Slackware or one you compiled from scratch), there would be no thing. I guess in that one case, you can make it even more optimal than OS X/iOS. Coming to Chrome OS: Chrome itself is a browser. All apps are written in JS which means you need to create opcode first or at least compile the JS in the first go. Not very bad but considering 'JS' - I would rather keep a little distance from it. Also, Chrome OS is Linux under the hood. Android: It runs on Java (okay okay, the apps runs in Java but the JRE/Dalvik keeps running). Java is Evil. Hence Android is evil. Add to that all the bull crap manufacturers add to it. Those crappy stuff is what makes Android bad (slow, buggy, resource intensive). In addition, whatever happened to 'we want to have energy efficient programs on mobile devices' theory.