You have a few options, all described here: Document and Deploy
To summarize:
- Through Mathematica Player (which you
could see as another type of Flash
Player and is thus an executable
meant to view Mathematica
notebooks).
- Through a Language API (which allows
you to embed Mathematica in your
language of choice, provided there's
an API for it. For instance, J/Link
or .Net/link for Java and C#
respectively. You can either use the programming language inside Mathematica, or create applications in the programming language that use Mathematica Kernel and objects.)
- Through webMathematica (which allows
you to deploy to webservers and make
your work accessible through a
browser equipped with the necessary
plugin)
There's a couple more options. But these are the ones more approximate to your requirements.