Chinese programmers write their own Skype client, able to call directly to Skype. This means they reverse engineered the Skype cloud, the Skype session protocols, encryption, and negotiated the audio codec settings:

Today I received a call through Skype from a friend at a company in China, except he told me he was not using Skype to call me. His company has successfully reverse engineered the Skype protocol and he wanted to call me in the United States to see how it worked between physically distant IP addresses. We talked for a little over nine minutes before the call dropped. Then I called him back using my Skype and we spoke for another three minutes.

The first time we talked there was a noticeable echo on my end. The second time the voice quality was good ol' Skype crystal clear. At present they only support placing Skype peer-to-peer phone calls and they have not yet implemented presence. They have plans to add presence, instant messaging, and a host of other features. Their end goal is to create a client 100% compatible with Skype. They sent me a screen shot of their software (below) and my IP address was 100% correct.