Compaq Computer and EMC have exchanged interface details for their storage systems, allowing each company to incorporate the other's storage systems into their grander designs, the companies will announce on Thursday. Compaq and EMC both are embarked on plans that would let their customers pool different manufacturers' storage systems into one larger pool that can be centrally managed -- a key improvement over the hodgepodge of incompatible designs that prevails today. To achieve this simpler world, Compaq and EMC agreed to share the interfaces to their storage systems, so one company's storage management software can control products from both companies. In a first phase, EMC has shared the application programming interfaces (APIs) of its top-end Symmetrix system with Compaq, while Compaq has shared APIs for its HS G80 modular storage systems, said Don Langeberg, marketing director for Compaq's storage software and solutions division. In a second phase, EMC will share APIs for its midrange Clariion line, and Compaq will do likewise with its top-end Enterprise Virtual Array. The move bolsters EMC's WideSky initiative, under which the company plans to have its Control Center software manage other storage systems from other companies, said Greg Eden, an EMC spokesman. Likewise, it means EMC's storage systems will become part of Compaq's VersaStor initiative to join many storage systems into a single pool, also to ease management headaches. Though customers long have wanted this simpler, less proprietary storage world, there have been technical and political differences that have been hard to work past. Now EMC, for its part, is being less proprietary about its hardware interfaces. Compaq was the first company to join EMC's WideSky program. "We'll work with others, too, as they open (their APIs) up to us," Eden said. But swapping APIs may not be the easiest thing -- they are the "keys to the kingdom," as Eden put it, and companies can be reluctant to give control to other companies. That requirement for cooperation could prove the downfall of EMC's new WideSky program. "We believe that EMC will need the cooperation of its partners for this initiative to succeed. Unfortunately, we think that this will be a tall order," A.G. Edwards analyst Shebly Serafi wrote in a research note Wednesday. "Just yesterday, IBM told us that EMC would need IBM's APIs to really manage IBM's storage; however, IBM may not be so willing to do so." More enterprise IT news in ZDNet UK's Enterprise Channel Have your say instantly, and see what others have said. Click on the TalkBack button and go to the ZDNet news forum. Let the editors know what you think in the Mailroom. And read other letters.