Skype has updated its new SkypeKit SDK beta to support Windows and OS X systems, meaning developers for those platforms can now add background VoIP and video call functionality using the service. Launched last month but only compatible with Linux apps, the SkypeKit SDK allows for so-called "headless" Skype integration where the app itself needn't be separately installed by the user.
The SkypeKit SDK lives alongside, rather than replacing, the existing Skype API, which is primarily intended for those producing apps and hardware that works in tandem with the official Skype app. Developers will initially be charged a “nominal” membership fee of around $20 for access to the SDK, which will be given out on an invitation basis. You can sign up for an invitation here.