Are there replacements for the reg commad on Mac OS X 10.9
As far as I can tell reg is only available in Lion (/usr/bin/reg and /usr/share/man/man1/reg.1). I haven't been able to find it in any other system version in the 10.6 - 10.11 range.

Executing it in 10.10 works but I think some hardware data is missing. E.g my CPUs weren't recognized and I can't list any PCI device. Depending on the hardware your mileage will vary.