UDF™ (Universal Disk Format™) is a platform-independent file system which is particularly useful on optical media. Adaptec UDF Volume Access is a UDF 1.5-compliant File System. You need it if you wish to read closed Adaptec DirectCD™ discs in a CD-ROM drive. It will not enable you to read open DirectCD™ discs. Note: ‘closed’ discs are sometimes referred to as ‘finalized’ or ‘finished’ discs. Mac OS 8.1 includes an Apple extension called “UDF Volume Access”. This supports volumes written to the UDF 1.02 specification. It cannot read DirectCD discs. Adaptec UDF Volume Access supports UDF 1.5. The two extensions can peacefully coexist. However, if DirectCD is installed, you need not install Adaptec UDF Volume Access in order to read UDF CDs in your CD-ROM drive because DirectCD’s file system contains all the functions of Adaptec UDF Volume Access.