Yak-42D is still in production at Saratov at the rate of one or two airplanes a year. In the early 90s more advance versions were developed Yak-142 and Yak-242.
Yak-142 is a partly Westernised version of the basic Yak-42D, with AlliedSignal avionics, but retaining the Progress D-36 turbofans.
I think Yakovlev have build two or three Yak-142 prototypes.
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Photo © David Unsworth
Yak-242 is intended to have AlliedSignal avionics and to be powered by two underwing 118kN Perm PS-90A12 turbofans. CFM56 and V2500- powered versions have also been studied.
Yak-242 exists only on a drawing board.