Juno-60 and DX7 are most certainly synths. I don't know enough about a Triton to say whether it's a ROMpler or a synth... I'm under the impression that the Triton is a ROMpler, synth, sampler, and sequencer all in one, but I don't know for sure. A better example of a ROMpler would be something like the Alesis QS8, and all the cheaper type synths that are basically used to imitate other sounds, whether they be real instruments or classic synth sounds (Rez Sweep, that kind of thing). A prime example of a ROMpler would be the GM "synthesizer" found in most computer soundcards. The Korg NS5R is a ROMpler that I've personally worked with, it just plays back sounds, you can play with the envelopes and filter a bit, but you can't really change the nature of the sound too much.