Maybe you'd like this then...
I hear that Lavasoft is using Viper's engine in their new suite product - which is still free - AdAware 10. However - since they were bought out by some shady concerns last January, I can't trust them on my machine - but I do encourage clients with little to lose, to continue using it. On those that did uninstall it - they quickly decided to return to using it - so that is proof in the pudding - as I see it.
Keep Up with TechRepublic