Qtel stands for the "QT EchoLink" client.
EchoLink is an amateur radio invention (well actually it is just a modified verison of IP telephony) to link radio transcievers together over the Internet. You must have an amateur radio license to use it.
The original EchoLink software can be found at http://www.echolink.org/. However, this software only supports the Windows operating system and it is closed source. SvxLink is released under the GPL license. Qtel is only a EchoLink client program.