Intel Desktop Ethernet E1000 Kext
This driver is based on Intel Wired Ethernet for Linux ( e1000.sourceforge.net ) . As it uses ( almost as is ) Linux driver's source code, the license is GPL.This kext is developed by Hnak.
The base Linux driver is e1000e-1.9.5 and works with Intel PCI Express ethernet chips like 82578 (P55/H55) and 82579 (P67/H67).
I tested 82573, 82574L, 82578, 82579 only as I do not have other NICs.
82575/82578/82580 based NIC needs another one - AppleIGB.kext.
Link Download available at url below :
Download Intel Desktop NIC Kext