This driver is based on Intel Wired Ethernet for Linux ( e1000.sourceforge.net ) and 82566mm OSX driver ( 82566mm-osx-driver.googlecode.com ). As it uses ( almost as is ) Linux driver's source code, the license is GPL.
The base Linux driver is e100e-1.1.2 and can work with Intel PCI Express ethernet chips like 82578 used with P55 chipset.
( I tested 82573 and 82578 only as I do not have other NICs. )
List of the IDs supported by original driver:
0x104B and 0x10F6 are supported by Apple's Intel82574L.kext ( so removed from this driver's Info.plist ).
2010/2/28: Sleep support.
Well, i read the whole thread, and realized there are many looking this kext for 10.5.X.
As i was in the need too, and its nowhere to be found, i went on, and compiled it.
So far, it is running flawlessly on an Alienware m15x under 10.5.8, on an Intel 82577LC (10eb:8086) network card.
Big thanks to the coder.. And below the link for anyone who might need it.
E100e kext for 10.5.X