DEmul is one of the longest running Dreamcast Emulators. It has been in active development since its first release all the way back in 2006, and is now regarded as one of the best Dreamcast Emulators you can get on PC.
Development of DEmul began after it became obvious that the development of Chankast has ceased and would not continue. Inspired by the fact an emulator could actually run commercial Dreamcast games, the DEmul team focused on getting there emulator to run thew vast majority of Dreamcast games while adding extra functionality that enhances the overall feel of the Dreamcast games.
Recent version of Demul have now gone as far as now making use of a DX11 rendering engine, giving it the speed boost that DX11 can bring but also sadly making it useless to older generation hardware.
DEmul is probably one of the best emulators available for the Dreamcast, and is definitely one of the more feature packed, the only emulator that can currently challenge it on performance and compatibility would be NullDC but Demul is the only one that is now actively in development besides Reicast. Seeing as Reicast is primarily designed so far for mobile devices, DEmul is the go to emulator for those who run on the Windows operating system.