> I would like to distribute a Ruby application that calls an
> external application. So far, I give the potential user the
> opportunity to enter or change some Gnuplot code, which is
> sent to Gnuplot via Open3 and produces some plot. Now, I
> would like to avoid asking the user to make sure he has
> Gnuplot installed.
>
> 1.) How can I ensure that everything that I need from Gnuplot
> is included in my application ? Is this done automatically by
> rubyscript2exe ?

No, it's not.

But, according to the RubyScript2Exe documentation, you can do
this: Put everything you need (your application and other
applications) in one directory tree, build an RBA from this
directory with Tar2RubyScript [1] and "compile" this RBA with
RubyScript2Exe [2].

All steps, including the rationale of both projects, are
described in [3].

gegroet,
Erik V. - http://www.erikveen.dds.nl/

 [1] http://www.erikveen.dds.nl/tar2rubyscript/index.html
 [2] http://www.erikveen.dds.nl/rubyscript2exe/index.html
 [3] http://www.erikveen.dds.nl/distributingrubyapplications/index.html