I've been thinking about this many times before and while I want to like the idea, I always come to the conclusion that multi user setups sharing "some" data easily becomes too complex for users to handle.
Your example of the browser for example, how do you know what is common config? What if changing a common config in cat-mode exposes a security vulnerability in bank-mode? And are you really going to log out of cat mode into common mode just to change a small setting?
Sharing files is another one of my favorites, say for example that me and my brother like the same music and share one computer with different log ins. We want to save space on the hard drive so we share all our mp3 with each other. But I might have some music or recordings I dont want to share, how should I handle that.
Windows XP tried very hard to get this working, for example your desktop and start menu was a blend of what was installed as a shared application (remember "install for all users/only for me"?) and what was installed for one user. Later if someone renamed things on what they thought was their desktop it would be renamed on everybody else's desktop also, it was very confusing even for me as a developer who knows how it works. Windows also has the concept of a dedicated shared folder and possibility to share additional folders, sounds so simple but I've never seen anyone set it up smoothly. Everything looks so good and simple on paper but requires just a tiny bit of user education and that's where the whole concept falls.
Your example of the browser for example, how do you know what is common config? What if changing a common config in cat-mode exposes a security vulnerability in bank-mode? And are you really going to log out of cat mode into common mode just to change a small setting?
Sharing files is another one of my favorites, say for example that me and my brother like the same music and share one computer with different log ins. We want to save space on the hard drive so we share all our mp3 with each other. But I might have some music or recordings I dont want to share, how should I handle that.
Windows XP tried very hard to get this working, for example your desktop and start menu was a blend of what was installed as a shared application (remember "install for all users/only for me"?) and what was installed for one user. Later if someone renamed things on what they thought was their desktop it would be renamed on everybody else's desktop also, it was very confusing even for me as a developer who knows how it works. Windows also has the concept of a dedicated shared folder and possibility to share additional folders, sounds so simple but I've never seen anyone set it up smoothly. Everything looks so good and simple on paper but requires just a tiny bit of user education and that's where the whole concept falls.