Hardware monitoring

Hi everyone, I know this is slightly off-topic, but since it's still related to the list, I thought I'd give it a try. I am wondering what systems are out there (open source, preferably) for data collection and processing of hardware health data (temperature, CPU clock, fan speeds, etc). Ideally brand agnostic and location agnostic as well. I know of Cacti, but it would require SNMP enabled devices AFAIK, so room/generator/misc monitors wouldn't necessarily be included. Thanks in advance. Rafael