Language for Web Application with User Configurable Scripting?

I'm an eager amatuer, and am rolling around an idea to use to 'sharpen my saw'. I want to start an app to allow;

creation of forms by the userbase
management of those forms
filling in of those forms
storing of forms

These forms would require some level of scripting (i.e add Field 1 to Field 2 and put the result in Field 3), Ideally it would be a web or very thing client (like Java), and store data in some form of DB.

I've got lots of ideas rolling around, but the first one, that I'm least qualified to answer, is which language (or languages) could be used for this, and include user configurable scripting ?

Solution

You can probably use any language you feel comfortable with for developing such an application as (for the scripting part) you "only" need to implement some interpreter for whatever scripting language you devise.

To reduce the number of wheels to reinvent, you should probably look out for a language that...

has a either a unified API for dealing with embedded scripting languages (like javax.script), implements the concept of homoiconicity or otherwise provides strong scripting support
brings a web application framework that you feel comfortable with
provides bindings for your favorite database
comes with good documentation

As there are lots of languages out there that will meet those demands, it's basically a matter of taste and / or occupational reasonableness. The usual suspects would probably be:

Java EE-based stacks (either best-of-breed or "integrated" solutions Seam)
Alternative JVM-based languages (like Groovy with Grails as web application framework)
Ruby with a web application framework like Ruby on Rails or Sinatra
PHP for easy hosting