.ABK File Extension
File Type 1Automatic Backup File
Backup file created by various programs, including CorelDRAW, Ability Office Write, and PrintMaster Gold; contains a backup of the a currently opened document or project; used to recover program data in the event of a computer crash or file corruption.
NOTE: ABK files typically are not meant to be opened directly. Typically, the program that created them will guide users in the process of recovering any lost data.
File Type 2Need for Speed Underground Audio File
Audio File used by Need for Speed Underground (NFSU), a car racing game; contains game speech, music, and other sound files; used to play sound effects and music during gameplay.
File Type 3Arena Opening Book File
File used by Arena, a freeware graphical user interface used by chess engines; contains "opening book" moves, which store opening strategies for an artificial intelligence player; may contain millions of predefined moves.
ABK files are used to reduce the computational expense of determining optimal strategies for the first several moves of a chess game.