Installable File System

The Installable File System (IFS) is a filesystem API in MS-DOS/PC DOS 4.x, IBM OS/2 and Microsoft Windows that enables the operating system to recognize and load drivers for file systems. The Installable File System (IFS) is a filesystem API in MS-DOS/PC DOS 4.x, IBM OS/2 and Microsoft Windows that enables the operating system to recognize and load drivers for file systems. When IBM and Microsoft were co-developing OS/2, they realized that the FAT file system did not offer some of the features modern OSes would require, and Microsoft began developing the High Performance File System (HPFS), codenamed Pinball.