At St Serf's our preferred option is a dual CD deck which has auto pause and instant queuing (designed for disco use). It can sometimes be quirky with home made CDs, so we always recommend to teams that they try their CDs either at the Technical meeting or at the time of their set move in.
We also have a DVD/CD drive which is more tolerant on home made CDs so can often play ones which out preferred deck can't.
One group in our festival uses their own computer, but we just provide a jack lead to link it to the mixer, so do not know what software they are using.
Fortunately it has now been a few years since groups have wanted cassettes!
