As use of object orientation far application development has increased
, many researchers have investigated the design of object-based progra
mming languages for distributed and persistent programming, This paper
concentrates on reviewing a number of such languages for distributed
or persistent programming, In each case, the focus is on the object mo
del supported and the mechanisms and policies employed in the implemen
tation of distributed or persistent objects, In particular, each langu
age reviewed has been chosen to illustrate a particular object model o
r implementation strategy.