Manufacturing With Linux?

lamanite asks: "I work for a large manufacturing company and we're looking to upgrade some of our older DOS-based systems to something more modern, specifically to support TCP/IP. However, we still need time-critical control over interrupts and low-level I/O. We're looking at VxWorks, but their licensing terms are pretty hefty. Are there any Linux distributions that would be applicable to our needs while still supporting common hardware platforms (x86 and 3Com/Intel network adapters)?"