Enterprise use of Ruby

Hi all.  The company I work for is developing an enterprise-class system
in Ruby (a web-based assessment evaluation and student information
system), using multi-tiered architecture, test-first development,
a PostgreSQL back end, under Linux.  We're planning on working toward a
user base equal to the number of teachers in Texas, and have had excellent
results with Ruby.  However, recently we've had trouble proving that
Ruby can scale to this level.  The lack of native thread support has been
cited as the major reason by the expert hired by our client.  The other,
which maybe someone here could help with, is the lack of industry support.
I already know we can get Ruby expertise in house; several people have
already expressed interest in working for our company (www.evalsoft.com).

The problem is that I can't find examples of real-world applications
supporting this number of users and the number of database rows we'll
have.  I don't personally believe it is proof of anything one way or
the other, but it is important to our client.

If anyone out there is using Ruby for such an endeavor, please email
me and let me know.  I am looking for major projects, with hundreds of
thousands of users, capability of hundreds of concurrent users, and
databases with several million rows in some of the heavily accessed
tables.

My own tests show that Ruby is performing as well as I'd expect, around
the same performance as equivalent perl or python, and much better memory
usage than equivalent java programs.  I could improve performance with
connection pooling (dbbalancer or sqlrelay are options, though we had
some instability when we tried sqlrelay in the past), but even as it
stands I think we are doing pretty well.  If I am being naive, I'd be
glad to have a rubyist point it out to me.


Thanks,
  Gabriel Emerson
  Evaluation Software Publishing
  www.evalsoft.com