>> I'm finding myself using Ruby with XML more and more. However, I'm
>> reluctant to distribute applications that use xmlparser, as it forces
>> the applications' users to install both expat and the xml module.

I must agree.  To put a different slant on this: The lack of XML as a native
part of the standard Ruby distribution was a deciding factor in using Python
2.0, instead of Ruby, for some tools I'm shipping with a wee C++ library I made.
I would rather have used Ruby, but didn't want to force my (admittedly few)
users to have to install and configure the xmlparser package.

And I figure that anything which was a deciding factor in making me use another
language when I would rather have used Ruby deserves some attention.

>Be very careful about "bundling" expat, and making it different to any expat
>already installed on the system, or even installed later for use with
>another application. 

That's true.  There's always the option of (aghast shock) static linkage to
avoid same, although it also avoids the ability to "swap out" for new versions
of expat as they come available.

-->VPutz