As we continue the march of Webifying everything, of BYOD becoming a pervasive part of professional life, and of more user tracking from websites at every level, we're currently ill-equipped to manage professional and personal Internet use. Most people don't know the difference and blithely combine the two. This is how so many professional email addresses were found in the Ashley Madison hack and how so many people wind up on the wrong end of the stick when they might access certain NSFW sites and become subject to corporate security measures -- even when the access is from their personal laptop.
I run three or four different Web browsers simultaneously at any given time. Usually it's Safari, Chrome, and Firefox. I tolerate the resource drain caused by this method for a few reasons, but the primary reason is task and usage separation.
I reserve one browser for personal use. This is where I'll do my casual browsing, news, aggregators, shopping, and whatnot. Another browser is earmarked for work. This is used for all the Web apps I use on a daily basis, everything from GitHub to various hosted service control panels, WebEx, custom apps, and so on. The work browser generally cannot leverage privacy tools such as Ghostery and NoScript because they interfere with normal app functions. Finally, I run a dedicated browser exclusively for social media because I firewall trackers as much as possible, and there are many sites that are nonfunctional on purpose if you're using blockers and privacy tools. Thus, those sites get to watch me use their site and track me nowhere else.
While mine is not perhaps a normal use case, it's not terribly far-fetched either. I'm sure there are many people who at least separate work and personal Web use by using Chrome for one and Firefox for another. This is a resource drain, and not altogether necessary. Some folks try to use Chrome's People feature, which is somewhat close in concept but functionally horrible for this purpose. Firefox offers profiles too, and you can create custom launchers to invoke multiple separate instances of Firefox with different profiles, but that's far less than ideal.
It should be possible for a single browser to create isolated instances -- not unlike the containerization used in mobile platforms, or separate virtual compute instances -- that are fully divorced from one another. These segmented browsers would not share cookies, sessions, plug-in settings, or anything else, but would be built around a single core. You would be able to switch among them like you switch among apps now, and collect groups of browser windows into the different instances for simple access.
First, this would help immensely with basic workflows. Instead of tabbing through a ream of personal-use windows to find your corporate webmail, you'd bounce to your Work instance and find a limited set of windows or tabs, never worrying about cross-pollination between instances. Ideally, this would be as simple as app switching is now.
To be clear, this is decidedly not simply organizing open browser windows into groups or using different profiles, but separating browser windows into silos that do not have any relation to other silos. They would exist in a discrete, isolated environment all to themselves and would be accessed as completely separate instances, not only profile assignments per window.
One method for this would be to run a VM for all work sessions, but again, if we're sticking to the premise that much of what we do is Web-based, this is unnecessary resource utilization. It could be that some underlying hypervisor may be warranted to build such a tool, but a full virtualized OS would be overkill. Further, we may want more than a mere two discrete sessions, and adding multiple VMs is even more wasteful.
The need to differentiate our personal and professional lives has always been important, but it has become a critical need with all the services we're now using that are on a common hosted platform for both work and home, such as Google Apps. At the same time, many are dispensing with the concept of a "work" and "home" computer, especially with mobile devices. Seamless but distinctive switching between these worlds on the same device in the same workspace is becoming a necessity.
I don't go to work and expect to enjoy a homebrew and watch a Red Sox game, and I don't go home and expect to find conference rooms and cubicles. At least in my browser, I should be able to separate those two domains as easily and efficiently.