# Middleware

This section contains topics about PX4 middleware, including PX4 internal communication mechanisms ([uORB](../middleware/uorb.md)), and between PX4 and offboard systems like companion computers and GCS (e.g. [MAVLink](../middleware/mavlink.md), [uXRCE-DDS](../middleware/uxrce_dds.md)).

:::tip
For a detailed overview of the platform architecture see the [Architectural Overview](../concept/architecture.md).
:::
