What soft edge blending solutions are out there?

DEXON® Systems is developer and manufacturer of DXN5500 projector wall controllers with soft edge blending capability. 

The DXN5500 system ensures outstanding display quality over the image of multiple front projectors. The soft edge blending capability guarantees wide and tall image while no gap can be seen between the individual screens. Sophisticated black level adjustment and easy-to-use gamma correction facilitate the setup of the projectors. The DXN5500 controllers provide perfect solution to meet various project requirements in the following applications:
• Conference rooms
• Meeting rooms
• University campus and auditoriums
• Classrooms
• Control rooms
• Security supervision systems
• Staging and rental applications
• Show and demonstration rooms