Note: I have found no list with the topic somewhat like ISDN-ENGLISH, so if you know a better destination for this question inform me, pls.

http://www.capi.org http://www.avm.de http://www.wuebben.org/members/markus/development/fmi/ http://www.capircvd.de www.isdn4linux.de (vorallem das Mailinglistenarchiv)

These sources are o.k., but if would like to obtain some OVERVIEW (which is hard to get in any linux topics which is the worst on linux anyways) on how CAPI4linux and ISDN4Lx compare and what each of them is able to do for you. Any direction you can point me to? *M*tia! Olli