I can comment on Firebird. The following changed since the first comparison:
Multi Threaded Architecture Available?
Yes (super server)
Actually, Classic Server is the preferred server type for scalability. Starting from Firebird 2.5 (currently in beta) there is also an architecture called SuperClassic. I wrote a small post on the differences: SuperServer, ClassicServer or SuperClassic?
Stores Transaction Information in same
file as data? Yes (in red)
I don't see how this could be a problem to be written in red. Firebird uses careful writes
to ensure the database structure is always consistent.
Temporary Tables? No
Available in Firebird 2.1. Release Notes
Rich Built in Functions? No
Firebird 2.1 also improved this. Release Notes
Multiple authentication methods(i.e.
LDAP) No
While there is no LDAP support, Firebird 2.1 allows Windows authentication. Release Notes
Create user defined types? No
I'm not sure what the author means here, but Firebird has had domains forever.
Require backup/restore to compact? Yes
(in red)
Arguable. Database space is reused. I find it hard to imagine the need to shrink a database in production.
Use POSIX Regular Expressions in queries? No
Firebird 2.5 (beta) supports regular expressions. Release Notes
Database Monitoring? No
Yes, Firebird 2.1 supports database monitoring via system tables. Firebird 2.5 adds support to trace facilities.
I know at least one excellent database monitoring tool for Firebird. ;)
Ability to query databases on other servers local or remote. No
Firebird 2.5 (beta) can query remote databases. Release Notes