Goals

FreeRTPS aims to be a "small" RTPS implementation capable of fitting in a variety of microcontrollers using only on-chip memory and flash. At time of writing, only the Ethernet physical layer is supported, but over time we hope to extend FreeRTPS to communicate (using gateways) across "smaller" physical layers such as various speeds of USB, various wireless standards (e.g., 802.15.4), various UART physical layers such as RS-485 or single-ended TTL, and so on.

FreeRTPS is provided under the Apache 2.0 license. This license is similar to the BSD license in many ways. It allows you to freely use FreeRTPS with just about anything. This article from Bruce Perens explains how the Apache License fits within the world of modern open-source licenses.