> First the cost is around US$35,000

As DB2 is not certified on current Server and Oracle is not certified
at all that amount of money is certainly not all to get the
certificate: For both IBM and Oracle it can be spend "out of the
pocket" - there certainly are other reasons not to certify.

For an Software that is free of cost noone will spend such an amount
of money to ceritfy it on an single Operating System.

Firebird is also not "certified" for Debian Woody, Debian Sarge, Suse
9.0, Suse 9.1, RedHat, FreeBSD, NetBSD, Solaris, AIX and others. Who
is going to certify for this OS? Who cares about "certificates" for
these OS?

Elmar