When critics have pointed out that the Microsoft Silverlight plugin lacks Linux support, fans have pointed to Moonlight, an independent open source Linux / Unix version designed by Miguel de Icaza's Mono project. But while Microsoft has merely backed away from Silverlight development, de Icaza now says that Mono is done with Moonlight altogether. "We have abandoned Moonlight," he says in a recent interview. "These days we no longer believe that Silverlight is a suitable platform for write-once-run-anywhere technology, there are just too many limitations for it to be useful."

Part of the reason for dropping it, he says, is simply a cost-benefit calculation. "Silverlight has not gained much adoption on the web, so it did not become the must-have technology that I thought would have to become." However, "Microsoft added artificial restrictions to Silverlight that made it useless for desktop programming" too, he says, contributing to its decline. Instead of Moonlight, he says users would benefit from having separate interfaces for each platform. Microsoft's latest version of Silverlight isn't too old yet, but the company may soon be following in the footsteps of Mono.