I've just spent several weeks commissioning an electrical system using proprietary software which is (a) old, (b) no longer being developed, (c) free issue (you pay for the hardware not the software) and (d) buggy or at best limited.

It is a good example of an application that would be much better open sourced (ok so I can't think of any that wouldn't be better that way, but that's not the point :-)

I thought I'd try emailing them and sounding them out, but on the assumption that their starting point will be a long way from where I want them to be are there any good "why you should open source your application" references I can direct to, which focus on the reasons relevant to my points a-d above, not the long list of other reasons we might also use ourselves?