Probably the most commented on experience from Mac OS 9 was the fact that once one application crashed, they were all in trouble; generally, you were in for a complete system reboot. At last OS X came along and solved all that, finally providing protected memory and the ability to force quit one application without affecting the others. People rejoiced as they left their computers running for days on end without needing reboots and uptimes soared.

Of course, deep down everybody loved OS 9 – even those who’d never used it. Everyone longed for the opportunity to sit back and relax while everything rebooted. They’ll never admit it, most of them don’t even realize it, but nearly everyone runs an OS 9 emulator on an almost daily basis. Not a complete emulator, but it reproduces that critical “me time” preserving feature of having everything in the same memory space. What is it? Your browser.

That’s right, your browser has it’s own OS 9 experience built right in. You get to load up all these different applications, email, word processing, spreadsheets, encyclopedias, music players and photo software – all living happily in harmony. That is until one of them hits a browser bug. Then they all just go away in the blink of an eye and you have an excuse to go get another cup of coffee and slack off for a while.

You might think that web sites can’t crash your browser – that would be a security risk right? At least a denial of service, if not a possible remote exploit. Of course it’s a security risk, but that doesn’t mean it doesn’t happen or even that it only happens rarely. The fact is, browsers are fickle things and when you combine that many different web sites doing all that stuff inside one process even tiny little bugs or small, rarely triggered memory leaks really start to build up and cause problems. That’s why operating systems moved to protected memory models and as more and more things move to the web, browsers are going to have to do more and more work to make sure that web applications, including long running web applications, are clearly separated from each other. It’s not even enough to make sure that the slate is wiped clean when a new page is loaded because so many applications sit on the same page working away for days on end now.

Browser makers are certainly thinking about these problems and gradually making progress towards solving them, but it’s certainly not there yet. I’ve simply not found a browser that can keep running as long as my OS can (OS X or Windows) without crashing, gradually slowing to a crawl or starting to show erratic behavior. In short, if the browser is the internet OS, it’s about on par with OS 9.