The program was inspired by the Linux Project. When installing Linux on a PC that was used for DOS / Windows, many people want to retain a smaller partition for their DOS software. However, since most Harddisks contain only one large partition, you would normally be required to do a complete backup, erase the partition and build two (or more) new partitions. Then you would restore the backup to one of the new partitions. On today's systems with hard disk capacities of usually 500MB or more, a complete backup becomes practically infeasible without large media like streamer tapes once the drive has filled up to some considerable fraction. Even though many people backup their most valuable date (a practice which I would highly recommend in any case), the process of reinstalling all the software packages takes many hours or even days.
FIPS was written to remedy this problem. You can now split a partition without losing any data, provided there is enough free space for the new partition at the end of the old one.
2. What FIPS does
FIPS reduces the size of a partition by changing some values in the partition table and boot sector. It does not change the formatting of the partition, especially not the cluster size and the size of the file allocation table (FAT). Therefore the reduced partition will have a FAT that is in part unused, but this is not a problem for DOS.
From the free space that is won by this, FIPS creates a new _primary_ DOS partition.
If you want to use the new partition under a different OS (e.g. Linux), use its supplied fdisk program to make any necessary changes (refer to the OS manuals).