When they ask, what is this written in?

[Mikey]

Consider the following to be constructive criticism, despite the tone.
 The tone is merely a vehicle to illustrate the point plainly.

1) R++ is already taken.
2) Why are you embarrassed about the environment?  If you are, then
you are talking to the wrong people.  From a different angle, if these
people and their money are going to have an enormous positive or
negative impact on your future, then you're an idiot for writing it in
any tool that you think is going to keep you from sealing the deal.
Conversely, you'd be an idiot for letting them have so much control
over your future and your baby if you're using Rev for any reason
other than it was dirt cheap and you're living at home with your Mum
who can't afford to fix the roof.
3) You're in Europe.  Rev is in Edinburough, Scotland.  How is that
possibly bad?
4) IMHO, nothing is worse than lying or trying to cover for your
inadequacies.  If you tried to pull a stunt like some of the ones that
have been suggested here I would toss you out in a second, which is
just about how long it would take to see right through you, and to be
clear, I've dropped many tens of thousands on individual software
projects and tossed a lot of vendors out the door for being ass
clowns. Tell them the stinking truth - the engine is open source with
commercial IDE/RAD toolkit built on top of it, and even that is open
source.  It uses a language and paradigm that started with HyperCard,
which makes it really, really easy to write and even easier to tweak.
It will run in Windows, the Mac or Linux without having to hack the
code all to hell.  The last major release was a couple of months ago,
and they are on a six-month minor, twelve-month major cycle.
5) Insulting C++ or M$ or Java is a Very Bad Idea, as is insulting
your competition.  This isn't a political campaign, and you don't
score points by setting fire to the opposition.  You do make folks
look for the gong, though.  If they're asking what tool it's written
in it's either because a) anything other than C++/Java/M$ whatever
isn't good enough, in which case they're not interested anyway, or b)
because they're interested in you and your project, and they're just
curious about how you pulled it off, because maybe they can try it
out, too.  Dropping your drawers and mooning them is a good way to
make a name for yourself, and not the kind you want, since you're
going looking for their money.  Mooning them will also surely make a
name for you with people they know, which also alienates that money.
There's also c) If you even mention C++, Java or M$, you're getting
tuned out, and there are MANY people who have had enough of all three.
5) Know what the weaknesses are, and have a reasonable response
planned.  Is it scalable?  Does it run in Linux - oh, wait, we already
addressed that one.  What about ad hoc reporting?  Licensing.  SaaS.
Email.  Web serving.  Costs of development seats.  There are major
software development vendors out there that have a difficult time on
several of those, where RR is fine.  How do we do version control?

They're a whole lot smarter when it comes to business than you are,
and they have a ton of projects they can invest in.  This isn't a
charity.  Almost none of them are interested in jerks they can't work
with.  Almost all of them are looking to get angel money into the Next
Big Thing.  What's the plan?  What's the target price?  Who's the
competition?  How do I integrate this tool with what we're doing?

Bottom line:  If you can't justify your decisions and investment and
expenditure in this project to this point, they won't be able to
justify theirs, so either hurry the hell up and rewrite it in
something else, or be comfortable with what you did and why, and stop
worrying about whether or not it's good enough.  They didn't invent
it, you did.