User mode file system library for windows; FUSE for windows.
What is Dokan Library:
When you want to create a new file system on Windows, for example to improve FAT or NTFS, you need to develope a file system driver. Developing a device driver that works in kernel mode on windows is extremley 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.