In 2005, Apple will release a new generation of Mac OS (5 generations), based on UNIX platform, Apple officially believes that the product's open source software will make him more secure than other proprietary software. Many operating systems now produce from the kernel, open source enable people to check the key parts of the kernel code. I want to do not know if Tiger will become the attack target of malicious code, but the previous Mac OS is a security vulnerability, but there is no more Windows and other competitors, (but I think this is related to the mainstream operating system, and Can't say it is safer, after all, the people who want to be famous are all went to go.)