GNU code in DLLs

[Kevin Grant]

Hi,

I have stumbled upon a commercial software package which contains GNU
GPL licensed code and has no source available for download.
Technically, I suppose they are not violating the GPL unless I ask for
source and they refuse (correct?) but I am unsure of how much source
code to ask for.

The application is windows based and is split into 50 or so DLLs, some
of those DLLs contain gcc-avr and sdcc compiler code, both licensed
under the GPL with copyrights held by FSF and Sandeep Dutta (I think)
respectively. I believe all the exectuable code is delivered in one
install, although purchased unlock codes are required to enable the
compiler functionality.

In this case, how much code should be made available to the community,
just that for the DLLs containing GPL code....or does it go further
than that? Does the inclusion of unlock codes to enable GPL code muddy
the waters?

I can supply a trial download link to the vendors website, but want to
be sure of my facts first.

Many thanks,

Kevin