I'd be tempted to offer my own services but too far away for me from here up North. A few points though. Firstly, I want to make the observation that it is always a shame when the relationship between a supplier and client breaks down to this degree - with both parties becoming entrenched. Part of the problem here is that this was allowed to happen in the first place. IF both sides are committed to maintaining their relationship, the chances of this sort of catastrophy lessen. Secondly, my experience of citrix is that the technology exists largely outside of the application set; apps run or don't but citrix doesn't affect them to a great degree (other than perceived speed, which is largely a bandwidth issue) once they are configured correctly. Where I have come a cropper previously is when applications interact and the citrix environment fails to deal with setting this up appropriately. Citrix itself I find to be great when it runs well; incredibly difficult to pin down when it doesn't, and I bet the supplier feels (quite confidently I'd add) that the difficulties the client is reporting are nothing to do with its app; which I'll bet runs elsewhere under citrix with no problems. Finally; my first point of call would be with whoever is responsible for installing and maintaining the citrix environment rather than any single application supplier. LEt them act as honest broker.