Since 2001 DECHEMA uses its own software system CongressEngine which has been continuously developed during that time. More than 100,000 participants have submitted their papers via this system. CongressEngine provides sophisticated Referee-Tools which allow also complex structures of big conferences to be modeled in a convenient way. The communications with authors and participants are highly automized but leave enough scope for special requirements. Programme structures can easily be generated and are available automatically on the web. An Application for Mobile Devices like Mobile Phones or Tablet Computers is generated also automatically.