In the database area, there has been some pressure 
to support richer semantic models than the now 
classical relational model. The pressure has been 
to support the object-oriented model. However, the 
larger market has not been willing to adopt a pure 
object-oriented model, but some of the major producers 
of database management systems have introduced systems 
which they call object-relational, trying to combine 
relational and object oriented technologies. This 
report embraces that approach, and takes the 
perspective that relations are a natural thing in 
modeling reality. Our notion of object-relational 
modeling is borrowed from Rumbaugh. The report 
describes the fundamentals of the model, it reports 
on experiments in implementing it in both an 
object-oriented language (Smalltalk), and a modern 
object-relational database (Oracle 8). It gives a 
brief outline on some preliminary experiences from 
a concrete modeling case, the rule-checker of the 
STADS system, and it points to some new directions 
which must be investigated.