Reply to The first DJ/Live Performance software?

What were the first DJ/Live performance softwares and when were they released?

I've had a little search around, VDJ seems to have came out 2003, Traktor dj studio (1998?), one called Virtual TurnTables that seems quite old but can't find a release date, Ableton (2002?)

Looking for examples of traditional 2 Sources + Mixer layouts and also anything more groundbreaking such as Ableton, i'm doing some evaluation of user interfaces.

Help is much appreciated