Awesome

SlowSoftWire

A wrapper for SlowSoftI2CMaster emulating the functionality of the Wire library (for master clients). In order to use it, you also have to download SlowSoftI2CMaster.

This has been derived from the Arduino Wire library and is published under the same license: the LGPL.

New library

This library has been archived! Please use the new FlexWire library instead. It is based on SlowSoftWire, fixes one bug, can act as a drop-in replacement for Wire (see my blog post on it), and has a new method called setPins, which can be used to change the pin assignment for the I2C bus dynamically, thereby supporting a kind of software I2C multiplexing.