Back in 1998 VJ-ing was done with VHS tapes and an mx50 video mixer so it was hard to quickly improvise video to music because tempo could not be adjusted, or even reversed.
Effects were limited to what the mx50 had to offer. We thought software would allow us to improvise more and be a better VJ.
We could not find any VJ software that did what we wanted back in 1998 so we started programming our own. We quickly realized our software was much better than our VJ-ing so we work on Resolume full-time since 2002.