Who can tell me what this is?

:?: :?: :?: :?:

Looks like a serger to me. ;-)

That was my first thought.

The four dials and the fabric cutter on the foot tell me its a serger.

Looks like a serger to me too....keep us posted.

Is this a prize puzzle?

Its a four thread serger. Each of the dials is for the tension of each thread. I am not seeing the thread stand for the four cones of thread , ( they may just not be in the photo).
Great little machines when they work properly. They stitch , trim and overcast all in one step. They create a very tidy seam.

Looks like a serger to me and from the other responses, will be surprised if it isn't.

serger