I have been using Intego Peronal Backup X5, Net Barrier X5, Virus Barrier X5 for some years. I currently am running them on a G4 Laptop and G5 Desktop with OS 10.4.11. I have never had a problem with any of their products and have always had quick response by email if I had a question. My experience is they have been superior. Great interface and updated regularly and easily. Intego produces 5 star products in my opinion. I also have Super Duper which is excellent backup software but I sort of lean to Intego Personal Backup.