The Pi4J Project was started in 2012, the same year the Raspberry Pi was introduced, as a tool to provide Java developers a simple and familiar object-oriented interface library to access the low-level I/O capabilities of the Raspberry Pi including GPIO, I2C, SPI, PWM and Serial communications.
The Pi4J project has evolved over all these years as the whole Java eco-system and Raspberry Pi systems have been evolving. This resulted in the following main versions:
In February 2026, Pi4J was accepted into the Commonhaus Foundation to ensure the continuity of the project. Read more about it in this blog post.