The 5rot hydraulic derailleur system was the brainchild of Christoph Muthers and was produced by Muthers Fahrradkomponentenbau. He was originally based in Freiburg in southern Germany - but this web site gives an address in Morscheid, not far from the border with Luxembourg.
I had seen the 5rot system at trade shows clearly branded ‘5rot’. However in 2011 5rot (and this web site) disappeared and the hydraulic derailleur system reappeared branded as the Acros A-GE system, with the rear derailleur called A-GE RD. Acros are an established German distributor of trick mountain bike equipment.