> I am new to FireBird and want to use it as a back-end to my .NET
> applications. I have few queries regarding this:
>
> (1) Is FireBird 100% ANSI-SQL compliant?

This might be a good reading:
http://www.firebirdsql.org/index.php?op=devel&sub=engine&id=SQL_conformance&nosb=1

> (2) Does it support advanced database features like replication,

Yes. Via third-party tools. I would recommend IBPhoenix' IBReplicator

> multi-version concurrency control (MVCC),

Yes.

clustering

Not for load-balancing. For fail-over, you might build up something with
replication and an appropriate middleware.

etc?

What else?

> (3) Which is the best GUI front-end for working with FireBird?

That's a religion. I would recommend Database Workbench, but I'm biased.
;-) There is also IBExpert. Flamerobin is cross-platform and free and
"comes" from the project, but hasn't the full-fledged feature set than
commercial tools.

> (4) Can it be easily connected to .NET (1.1/2.0) and what performance
> level is achieved with .NET applications?

Check out the newsgroup Alan has mentioned.

> (5) Does it have an automated backup feature?

Firebird 2 has two approaches for backups. gbak and new in V2, nbackup.
Both can operate on a live database, so online backups are possible.
Anything else, like time-scheduled backups and such are gimmicks and ca
be achieved via time-scheduling facilities of the OS or there are GUI
driven backup tools as well.


--
Best Regards,
Thomas Steinmaurer
LogManager Series - Logging/Auditing Suites supporting
InterBase, Firebird, Advantage Database, MS SQL Server and
NexusDB V2
Upscene Productions
http://www.upscene.com