I use Bike–and OmniOutliner–to “run my life”. I’m a web developer, and keep an outline for each of my clients that contains all the information I need to work with their sites. Each outline has a fairly standard format: Acct Information, General Information, History (records of meetings and actions), and Projects.
I use a similar format for personal projects I’m working on. Then there are special outlines with information relevant to the different businesses and other parties I work with in both personal and work lives. Then “aging” outlines, where notes I’m probably not going to need anymore get moved and then deleted after 30 days or a year, depending. And finally a priority-sorted “To Do” list with information supporting each item hierarchically contained beneath it. And, of course, an “In Box” where things get entered in meetings, conversations, or when a thought occurs–later to be organized.
After too many past experiences becoming dependent on an outliner that was discontinued and left me with an information “crisis”, I now make sure I’m using two products, so if one gets discontinued I can still migrate my outlines to the other. Right now Bike is the only outliner I’ve found that can compete with OmniOutliner in terms of (stability and) getting the outline concept right. And I definitely prefer its “open” file format.
In answer to your question, I keep my Bike outlines in Bike files, and keep them in a super-secure location since they include confidential information. I’d be hesitant to use a “library”-based product because of both security and stability concerns.