Open Source Network Management System.

OpenWISP is a modular network management system built on top of OpenWRT (but designed to allow supporting multiple embedded operating systems) that allows managing and automating several aspects of IT network deployment, monitoring and management.

OpenWISP @ GitHub

Internet connection bonding.
OpenMPTCProuter use MultiPath TCP (MPTCP) to really aggregate multiple Internet connections and OpenWrt.

The LEDE project is a Linux based embedded meta distribution based on OpenWrt and targeting a wide range of wireless SOHO routers and non-network devices