The Merant driver (also referred to as the Intersolv driver) that was once supplied by Borland, was only a ODBC 2 driver. It was only available for Windows, and only supported versions of InterBase up to 5.
Because of the lack of ODBC 3 features the old driver does not work with many current ODBC applications and is unable to take advantage of the new features in later versions of InterBase.
The Easysoft driver, was designed from the beginning for ODBC 3.5, and supports all the new features provided by InterBase version 6, 6.5 and 7, while also providing backward support for previous versions. It supports the ODBC UNICODE API, and is available for all platforms that are supported by InterBase.
For some years now the Easysoft InterBase driver has been supplied by Borland (ANSI only version) as part of their InterBase disributions, and is also provided with some of their other products, for example Delphi.