MIDI real time tuning is a general MIDI standard. Scala is just a program somebody wrote to make the creation of alternative scales easier. If your synth supports the MIDI tuning standard you can change its tuning by just sending the right sysex message, nothing to do with Scala.
Some synths I know that support it: Marion MSR-2, Waldorf Microwave, most of the Dave Smith / newer Sequential Circuits synths, Yamaha DX7II and the TX802.
Also I just discovered recently that the Cirklon supports real time tuning changes of its CVIO tuning tables.