[soylentcola]

Speaking as a layman here, but would it be trivial for actual-Skype to be tweaked in such a way as to break a compatible client that only currently works? Reminds me of all the third party clients or plugins for (insert service here) that work great...until something changes and it stops working.

[niftich]

Yes, it'd be trivial. In fact, this has pretty much happened with every single IM protocol at some point that was subject to reverse-engineering efforts. Here's some history from the early 2000s [1]. Libpurple changelogs are also enlightening.

[1] https://en.wikipedia.org/wiki/Trillian_(software)#History

[ultramancool]

Trivial to break, yes, but also trivial to fix usually. Once the initial RE effort is done, minor obfuscations to the protocol are typically not major harms.

[skypeopensource]

And break all the mess of 10 mln users online at once, and around 500 mln at month. With big zoo of various versions. Even if they do so, reversing new tweaks not take too long.

Also, you have good working proto. Do changes to it daily... For that reason? Just because someone write compatible client (very buggy, by the way, and less of features)? I dont think so.

[jpalomaki]

On the other hand, that kind of changes might generate negative PR. Something Microsoft might want to avoid.

Also given Skype's large deployment base, pushing radical changes to the protocol may not be a trivial task.

At some point there was also some hardware devices with Skype support, but I'm not sure if those work/exist anymore.