I'm currently working on a component of a trading product that will allow a quant or strategy developer to write their own custom strategies.  I obviously can't have them write these strategies in natively compiled languages (or even a language that compiles to a bytecode to run on a vm) since their dev/test cycles have to be on the order of minutes.
I've looked at lua, python, ruby so far and really enjoyed all of them so far, but still found them a little "low level" for my target users.  Would I need to somehow write my own parser + interpreter to support a language with a minimum of support for looping, simple arithmatic, logical expression evaluation, or is there another recommendation any of you may have?  Thanks in advance.
Define the language first -- if possible, use the pseudo-language called EBN, it's very simple (see the Wikipedia entry).
Then once you have that, pick the language.  Almost certainly you will want to use a DSL.  Ruby and Lua are both really good at that, IMO.
Once you start working on it, you may find that you go back to your definition and tweak it.  But that's the right order to do things, I think.
Scripting language for trading strategy development