these are a bunch of more complicated instruments in cmix cmbplk will perform a variety of plucked string things to sounds etc flange is a simple flanging instrument iir is an instrument which can stack up multiple two-pole filters multicomb can stack up a bunch of comb filters slider is a simple glissando/additive synthesis instrument the respective data files contain information on running these instruments
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.