lshw (Hardware Lister) is a small tool to provide detailed information on 
the hardware configuration of the machine. It can report exact memory 
configuration, firmware version, mainboard configuration, CPU version and 
speed, cache configuration, bus speed, etc. on DMI-capable x86 or EFI 
(IA-64) systems and on some PowerPC machines (PowerMac G4 is known to work).

Information can be output in plain text, XML, or HTML.

It currently supports DMI (x86 and EFI only), OpenFirmware device tree
(PowerPC only), PCI/AGP, ISA PnP (x86), CPUID (x86), IDE/ATA/ATAPI, PCMCIA 
(only tested on x86), USB, and SCSI.

On x86, lshw needs to be run as root to be able to access DMI information 
from the BIOS. Running lshw as a non-root user usually gives much less 
detailed information.