Development of the filter synthesis software Filpro were started about 30 years ago in DOS, Pascal. It had accumulated a vast amount of knowledge on filter synthesis and circuit transformations. It is still in DOS, hence not operating in new windows versions. Therefore it is no more available commercially. However it is still a very useful tool (on Win-98 or XP) which can cope with complex filter design problems. Some novel design approaches on Filpro will be presented in this talk and some design examples will be presented as separate papers in this session, all related to research works in Aselsan Military Ind.