Perhaps the world's first hack took place around 5,000 years ago after the advent of the abacus, a tool many describe as the original computer. The imagination can easily conjure up images of a student performing calculations on the racks of sliding beads. As he turns his head for a moment, a fellow young scholar tiptoes by and moves a few beads around in jest, causing the other to re-start his work from scratch. Had the student kept a watchful eye on his abacus, it is likely his work in progress would have been safe from the playful intruder.

When Unix was developed in 1969, the thought of stepping out of the punch card era was much more romantic than the idea that people might dedicate time to breaking into computer systems. But nowadays operating system security is more of an issue, as people trust their most confidential information to hard drives. And-even with firewalls firmly in place-it is the OS that remains the front line against intruders; holes in it can render even the most powerful firewall useless. We have to rely on operating systems to do most of that work-and keep strangers' hands off the beads. Here's an overview of the major presences in OS development and the ways they address ever-changing security trends and consumer needs.

Unix

Because Unix was originally designed as a more-open operating system, and thus there is widespread access to the source code of many of its “flavors,” anyone with the time can bang out code to patch holes and expose vulnerabilities. While that's been a boon for programmers and hackers, large corporations want some accountability for security. The various commercial distributions of Unix-from Sun, HP, IBM, and others-were developed to meet that demand. (The same is true for Linux, the open-source Unix flavor that has exploded in popularity. See the sidebar, “The Linux Alternative.”)

Hewlett Packard first released HP-UX more than a decade ago. Now at version 11i, it features security options from the IP level inward. According to Ram Appalaraju, director of marketing for HP-UX, the OS is scalable, secure, manageable, and operable with Windows. “UX is standards-compliant architecture, so any Unix operator can feel comfortable with it,” he said. “On the network level, all connections on the IP level are secure with full-level integration with any front-end system.”