dbExpress is a relatively new database access technology from Borland. It is designed to replace the old Borland Database Engine (BDE).
dbExpress is cross platform. It operates under Windows and Linux whereas the BDE and Microsoft's ADO only operate under Windows. This may be an important consideration for organisations trying to reduce costs.
dbExpress is fast. This is a result of dbExpress being a thin piece of code over the underlying DBMS's API.
dbExpress is very small. Again as a result of being a thin layer of code, dbExpress is about 4% of the size of the BDE. This can be a considerable advantage when distributing applications.