Original Arduino board and Ethernet shield may seem to be too expensive for some projects, so there is another solution – build Ethernet Arduino compatible board that could do same business. Ethernet is implemented by using Microchip ENC28J60 Ethernet chip that is actually in DIP package what makes simple soldering.
As it is a custom made Arduino, it isn’t pin compatible to other shields. But there is no problem to interface lots of things like temperature controllers or other stuff. And yes, it is more compact than regular Arduino and Ethernet shield combination.