Many people want to write filesystems, or things that look like filesystems, for Neutrino. The easiest filesystem to understand is a RAM-disk, because we don't need to deal with the "on-media" format — all of our data is stored in RAM, and the data itself is simply allocated from the pool of available memory. Reading, writing, seeking, block management, pathname parsing, directory management, etc. are discussed. This is an extensive chapter that serves as a foundation for the tar Filesystem Manager chapter (immediately following) and also serves as a good basis for any projects you may wish to pursue that need a filesystem (or a filesystem-like) interface.