I lead a project that included shipping a filesystem driver and a virtual disk on Windows. What I did to learn the lower-level APIs, and perform initial testing on the driver, was write a "mirror" drive. The user-mode code pointed to a folder on disk, the driver made a virtual disk drive, and all reads and writes in the virtual disk drive went to the mirror folder. On Windows, you can implement something like that... - Source: Hacker News / almost 1 year ago

I've day dreamed about having a tag based file system where a file path (URI) in which each segment is a tag. So path /image/red is the same as /red/image. File extensions would be part of the tags too. Been a while since I looked at my notes, but I think I originally was thinking of searching /red would show all files that have that tag ranked. File system base is nice because then the custom system works for... Source: almost 3 years ago

Apache Karaf with OSGi works pretty nice using annotation based dependency injection with the declarative services, removing the need to mess with those hopefully archaic XML blueprints. Too bad it's not as trendy as spring and the developers so many of the tutorials can be a bit dated and hard to find. Karaf also supports many other frameworks and programming models as well and there's even Red Hat supported... Source: about 3 years ago