Btrieve is a transactional database (navigational database) software product. It is based on Indexed Sequential Access Method (ISAM), which is a way of storing data for fast retrieval. There have been several versions of the product for DOS, Linux, older versions of Microsoft Windows, Windows 98, Windows NT, Windows 2000, Windows XP, Windows Server 2003, 32-bit IBM OS/2 and for Novell NetWare.