The co-author of the Illuminati series passed away January 11th. The Telegraph has an excellent obit:
His webpage has a brief mention:
If you've never read any of his work I highly recommend it but be warned. It isn't light beach reading and you may need a few days afterwards to process it. It's the sort of stuff that, even when he is being silly, gets into your head and plays around with the software. Maybe especialy when he is being silly.
Here is his Wiki entry for more info