"We got deobfuscated skype v5.5!!! I can't belive in this. But its fucking true. Great thanks and congratulations going to Vilko," begins a new post on the skype-open-source blog.
Additionally said by this community-focused project to provide an open-source Skype implementation, "Skype version 5.5 is a hybrid of GUI on delphi and embedded dll with skype "kernel". This kernel is fully independent structure in binary code - code block, data block, imports. And it was built with use of VC compiler(exists VC lib signatures). This kernel has not contain any reference to external code/data in delphi part. And only entry point block xrefs on kernel from delphi GUI. It can be saved as independent binary code with dll-header, and that kernel will work, i tested this." Basically this means they could implement an (open-source) Skype client independent from the main Skype GUI.
It was last June that I originally reported on the Skype client being reverse-engineered, which is when the Microsoft-owned Skype informed me they were going after the reverse-engineers citing "nefarious attempts to subvert Skype's experience." Microsoft/Skype began volleying DMCA take-down notices towards this open-source Skype work. After a few months, not much was heard of on this Skype reverse-engineering work until now.
The original Skype reverse-engineering work was upon an older version of Skype, but now with this latest attempt they are up to version 5.5. With the new version it illustrates more potential since the core code is separated from the GUI layer, but still Microsoft/Skype is likely to take action. With that said, and the fact that they're decompiling/deobfuscating the code as opposed to another clean-room reverse-engineering approach, I wouldn't expect to see open-source Skype support land in any popular open-source desktop programs in the foreseeable future.