Hosts CPU(s) with some features masked out - the max. # of VCPUs per VM is 4
Up to 64GB memory, minimum is 4MB
Intel BX chipset
Standard Floppy controller
NEC IDE CD-ROM
VMware SVGA II PCI VGA
Intel 82371AB/EB PCI IDE
PS/2 mouse or VMware Pointing Device (depending on the presence of the VMware tools)
AMD PCnet or VMware Accelerated AMD PCnet (depending on the presence of the VMware tools) or Intel E1000 NIC(s)
Buslogic or LsiLogic SCSI hostadapter(s) (max. 4 of them)
Standard serial (max. 4) and parallel (max. 3) ports (National Semiconductor SuperIO chip)
SCSI disk(s) with a max size per disk of 2TB

Six virtual PCI slots are available, two of them consumed by the VGA and one SCSI hostadapter

See also http://www.vmware.com/pdf/vi3_35/esx_3/r35/vi3_35_25_config_max.pdf

Message was edited by: oreeh

Here are the ones for ESX 3.01 (I haven't found a doc for ESX 3.5)
Click through them or use the "show navigation" button on the top left.
The virtual HW has changed slightly since ESX 3.01 (for example more memory per VM) - check the above mentioned config max pdf for differences.