A simple search on google gave me [this page](http://filext.com/file-extension/adf) as the first hit. Here is some information from that site… @filext.com: > Detailed information for file extension ADF: > Primary association: Game > File classification: Game > Related links: WATTO Studios Game Extractor > Other applications associated with file type ADF: > > A.R.S.E.N.A.L. Extended Power (Main Game File) by Tactical SoftA.R.S.E.N.A.L "Extended Power" is a real time strategy game based on 2nd World War units. 40 different units are featured over GROUND, AIR and SEA: 15 ground units, 10 navy units, 10 aircraft and 5 fixed defense units. This file is called arsenal2.adf (Arsenal Data File). > Actual Drawing FileProgram ID: Actual_Drawing_Data_File > Adapter Description FileA file often used with the IBM Microshannel Architecture. Found on a floppy disk included with hardware the file described the hardware to the computer allowing a more automatic setup to take place. Related links: ADF Info > Admin Config File > Amiga (Disk File) by AmigaUncompressed 901120 byte DD Diskimage. The identifying characters used for this association are - Hex: 44 4F 53 , ASCII: DOS Related links: Amiga Forever, FAQ, Emulation Newbies Start Here!, Emulator Zone > Antenna Data File The identifying characters used for this association are - Hex: 52 45 56 4E 55 4D 3A 2C , ASCII: REVNUM:, > ArcView (ARC/INFO Coverage Data File) by ESRI Related links: GIS Info