In computing, romfs (ROM filesystem) is an extremely simple file system lacking many features, intended for burning important files onto an EEPROM. It is available on Linux, and possibly other Unix-like systems.
It is very useful as an initial ROM holding kernel modules that can be loaded later as needed. It is very small, code wise.
Bo Brantén has created a RomFS file system driver for Windows NT/2k/XP.
Nikolay Aleksandrov has written RomFS image extraction and manipulation tool called romfser. Primarily targeted at the BSD family of operating systems because they lack support for RomFS.