Originally downloaded April 12, 2007.
The basic concept here is simple, and quite appealing at first glance: Instead of maintaining separate user profiles in order to segregate specific preferences, settings, and content for various applications, simply maintain separate profiles for each application. As easy as the Mac OS X quick-user-switching is, it's still not a piece of cake to maintain multiple desktops, global settings, and application collections, especially if you are working across different computers or have a particularly complicated account setup. RooSwitch comes in both a shareware and a "lite" (free) version, the main differences being that the free version excludes AppleScript (and Automator) support and is restricted to a set of six basic applications: Address Book, iTunes, iPhoto, Mail, Safari, and Stickies. Also, the full version lets you open multiple rooSwitch documents at the same time, whereas the lite version has all the profiles in one window. In any case, it's great the developer is providing so much flexibility, and I'm quite anxious to try this out! As he points out, such a tool has particular relevance to anyone who does software development, but I can imagine a lot of non-geek users might find the free version quite "liberating" in the way they use apps like Stickies. I recommend you watch the 4-minute screencast as a first step if you decide to try rooSwitch out. The full version, by the way, is $15.
Version as tested: 1.1.8. (Lite: 1.0.5)