Migrated from code.google.com/p/dokan. The original description:
When you want to create a new file system on Windows, for example to improve FAT or NTFS, you need to develop a file system driver. Developing a device driver that works in kernel mode on windows is extremely difficult. By using Dokan library, you can create your own file systems very easily without writing device driver. Dokan Library is similar to FUSE(Linux user mode file system) but works on Windows.
This project is no longer maintained! Check out the Dokany project, as it is a much newer and up-to-date fork.