[Koha] Koha with a proprietary frontend?

[Jonas Karlsson]

Hello,

I ask on behalf of a a Swedish library that wants to replace it's current ILS with an open-source one as part of an open-source initiative
and is considering Koha. The (potential) problem is that they have recently had a custom web-based frontend (opac) created that they are
very happy with and do not want to replace with Koha. This frontend is a proprietary solution that neither they nor the company that helped
them write it want to take open source.

In other words, they want to use the Koha backend with their own frontend (they do realize that they will most likely have to change their
frontend to interface properly with Koha.)

Would this be a problem from either a legal standpoint (as Koha is GPL-licensed) or a technical standpoint (i.e. is Koha's frontend and
backend so tightly integrated it would be difficult to do this)?

Has anyone on this list done something like it?

Yours,
Jonas Karlsson