The momentum Linux has gathered as both a server system and, more recently, a viable desktop alternative is in danger of being impeded by growing disharmony between developers and vendors, according to experts. One Linux developer based in the US, Craig Knedsen, says that cracks are beginning to emerge in the relationship between developers and companies. "Most vendors have a marketing division that is somewhat out of touch with the development staff," he says. "They often make promises and then come back to the development staff to ask if what they promised is possible, or if the promised schedule is possible." Alan Cox, a long-standing Linux kernel developer based in the UK, agrees that, although Linux developers work in harmony with big business for the moment, certain fundamental differences could cause problems in the near future. "A lot of the major Linux hackers work for vendors and although hasn't caused any friction yet, obviously the potential is there," he says. "We already have some disagreements. Some vendors don't get the 'release early, release often' idea." Most companies are accustomed to developing software over a number of years before allowing it to be released. The open-source movement encourages the concept of releasing software to the wider community after very little initial development. The theory is that this process allows as much development and testing as is possible to go into the finished product. Kirsten Ludvigsen, an operating-systems analyst at IDC Research in Denmark, agrees that some Linux vendors are failing to grasp this point. "I haven't seen much evidence of companies adopting this," she says. "There are some disadvantages to incremental development, in that it is less feasible to develop complex projects, but it can also be very good to develop software in parts. It can make it better for users when parts are developed separately." Knedson however also maintains that for the moment at least, Kernel developers are standing firm. "I'm not sure how these disagreements would affect a Linux kernel developer since, to my knowledge, no commercial entity has influence over kernel development," he says. Cox also believes that, even if it takes longer for Linux to become a mainstream product, enthusiasm among true believers will never waver. "I think the spirit will remain," he says. "You need something to believe in to have that kind of a movement. We have a community of people who seem to like Linux because it's not Microsoft. If anything they are the people more likely to be worried by Linux becoming too commercial."