Typhoon is a freely available relational database management system for
the UNIX and OS/2 environments. 

The system works fine and is currently used in a number of professional
applications in Denmark, some of them mission critical.

The system was originally inspired by Raima's db_VISTA (today Raima Data
Manager) but is relational rather than network based. Typhoon lacks some of
db_VISTA's features, but also contains a number of nice features not found in 
db_VISTA.