Skype owns anything developed on the SkypeAPI.
“Skype EULA wrote:
3.3 You acknowledge and agree that any IP Rights arising directly from the API are the exclusive ownership of Skype or its licensors without any compensation to You. Insofar as necessary, this Agreement serves as a deed of assignment of all of Your right, title and interest in and to such API modifications to Skype, notwithstanding Your obligation to cooperate with Skype in order finalize any other deed upon Skype’s first request. You hereby irrevocably waive to the extent permitted by law any moral rights relating to YourAPI modifications. You furthermore represent and warrant that (a) You are authorized to assign Your rights as stated above and (b) Your API modifications are correct and accurate and (c) the API modifications do not infringe upon any third parties’ rights, including but not limited to intellectual property rights.”
So much for a ‘free service’. I don’t know how many solutions there’ve already been developed on the SkypeAPI. Let’s hope these people were aware of the ‘little notes’ in the contract.