FAT16

The FAT16 file system was used in the days of DOS. FAT is an acronym for File Allocation Table. It is a 16 bit file system with a 2 gigabyte limit on the size of a partition. It stores all filenames in the 8.3 format (meaning that a file could have an 8 character long name as well as a 3 character long extension to declare its type).

The FAT16 was succeeded by VFAT in Windows 95 (which was the same but stored two copies of a name to allow filenames up to 255 characters long) which was in turn obsoleted by the FAT32 file system that allowed 32 bit transactions in addition to the improvements from VFAT.

Pros and Cons
FAT16 is a useful file system for use on floppy disks as it is very efficient with regards to size since its structures are very small (as are most FAT file systems). However, it isn't the best of file systems to use if you have enough space available for the larger structures of other file systems due to both the aforementioned 2 gigabyte partition limit and 8.3 filenames but also, FAT stores data wherever there is the space for it, causing fragmentation and slowdown (which can be repaired with a defragmenter). Most modern file systems don't suffer from these problems or do so to a lesser degree.

Linux Support
The Linux kernel has has fully functional, safe read-write support for the FAT16 file system.