Hello JerryM, long time no talk. Hope you are well. f-secure uses kaspersky version 6 sdk engine. kaspersky 2009 has a completely brand new rewritten engine from scratch and also has brand new heristics. f-secure uses its own inhouse engines as welll as deepguard 2.0 for proactive detection. as soon as you excute the files deepguard will jump in. kaspersky only started improving its heristics with version 7. kaspersky only sells engine plus signitures and doesnt include the heristics or any heristic updates as far as i know. I hope this helps you better understand the difference. f-secure is a fine AV and still excels in detection. its ondemand heristics have never been good.