.mdb - Microsoft Access database
.accdb - Office Access 2007 database file format
.mdf - Microsoft SQL Server primary datafile
.ldb - MS Access Record-Locking Information
.ipd - InstallPROG 6 EDBS install database
.fdb - Database file
.dbf - Database file
.rem - ACT! database maintenance file
file extension WAT - WATFILE file
File extension WAT description:
The ".WAT" extension was also used and developed by the University of Waterloo and WATCOM for a data manipulation system called "WATFILE". This was used for small to medium data sets, and was especially suited to cleaning up and standardizing entered data. It essentially was a command-line database with some very flexible and spreadsheet type capabilities. WATCOM is best known for FORTRAN compilers.
WATFILE (WATerloo FILE system) was developed between 1973 and 1983 by Prof. J. W. Graham and associates. It was developed to assist the Director of Computing Services at University of Waterloo with the manipulation of large amounts of data (i.e. service records, costs, mailing lists, etc.). The many suggestions of WATFILE's users resulted in changes and additions and led to the creation of WATFILE/Plus, a powerful, easy-to-use data manipulation system.