This is a DDS Function Generator by Theodorou Gerasimos from Elektor Magazine.
DDS chips are readily available, greatly simplifying the design of the analog part of a wide-range function- or signal generator. All you need to do (they say!) is choose one, add some suitable output circuitry, pick a microcontroller, provide a user interface and start programming. To which we reply: sweet dreams, here is the real story: power to the AD9834!
Elektor DDS Function Generator – [Link]