EtherCard
EtherCard is an IPv4 driver for the ENC28J60 chip
... easily push the limits of smaller microcontrollers. This library uses the SPI interface of the microcontroller and will require at least one dedicated pin for CS, plus the SO, SI, and SCK pins of the SPI interface. An interrupt pin is not required. Any Arduino IDE >= 1.0.0 should be fine. EtherCard is available for installation in the Arduino Library Manager. Alternatively, it can be downloaded directly from GitHub.