dBASE II was the first version of dBASE, a 16-bit command-driven program for CP/M and subsequently DOS. In 1984, dBASE III upgraded the DOS version with more features and support for larger databases. In 1986, dBASE III PLUS added the ability to store queries and relational views. In 1988, dBASE IV added support for SQL.
In 1994, dBASE 5 for Windows added objects and visual programming and provided connectivity to a variety of SQL databases using the Borland Database Engine. In 1995, Version 5.5 was renamed Visual dBASE, and a 32-bit version (Visual dBASE 7.0) was developed in 1997. In 1999, dBASE Inc. acquired dBASE from Borland and upgraded both versions of Visual dBASE, the 32-bit version subsequently becoming the engine in dBASE Plus (which was named dB2K for a short time).
Version Bits Year OS
dBASE II 16 1981 CP/M
dBASE II 16 1982 DOS
dBASE III 16 1984 DOS
dBASE III+ 16 1986 DOS
dBASE IV 16 1988 DOS
dBASE 5 16 1994 Windows
Visual dBASE 5.5 16 1995 Windows
Visual dBASE 5.7 16 1999 Windows
Visual dBASE 7.0 32 1997 Windows
Visual dBASE 7.5 32 1999 Windows
dB2K 32 2000 Windows
dBASE Plus 32 2002 Windows