About 50% of these are from HD installed files, and the rest use WHDLoadCD32. I'll add a recommendation tonight that if people use the CDs that they register WHDLoad to provide support to the coder.
@alexh - I'm not sure why you're so negetive towards me; I'm not doing this for kudos. Frustrated at the number of non-working unofficial CD conversions out there I decided to make some single game CDs for myself, and after I'd finished I thought it would be a nice gesture to share them - that's all. I'm well aware of the excellent work that Gary, etc. did with the 200, 333, 444 and 888 discs, but I only wanted to play a few of the games on those compilations and browsing through them to find one game can be slow work. I hope this explains my reason for doing this and there are no bad feelings?
@Akira - yes, there will be regular-ish updates. For a start, I'm working on a Turrican collection at the moment, and some of the other CDs on the page will probably end up becoming 2-4 game compilations (I intend to group Cybernetix on a CD with the rest of Vision's early games).
(oh and by the way, many thanks to woody.cool for submitting Virocop!)