open source
overview
Open source has been part of Mandelbit’s work since the beginning.
We actively contribute to major open-source networking projects and help companies bridge the gap between community-driven development and commercial products.
Our experience as contributors allows us to work effectively at the intersection of upstream projects and production systems, ensuring long-term maintainability and alignment with open-source ecosystems.
why open source matters in our work
For Mandelbit, open source is not an ideology or a marketing statement.
It is a practical foundation for building reliable, transparent, and maintainable networking systems. Working upstream gives us deep insight into how projects evolve, how decisions are made, and how to implement changes that can survive over time.
This approach helps our customers avoid technical debt, reduce long-term maintenance costs, and build products that remain compatible with upstream development.
selected open source projects
B.A.T.M.A.N. Advanced (batman-adv)
A Layer 2 routing protocol implemented in the mainline Linux kernel, designed for multi-hop wireless mesh networks.
Mandelbit has a long history of contributions to batman-adv and supports customers in extending, customizing, and deploying mesh networking solutions tailored to real-world use cases.
Linux Wireless Stack (cfg80211 / mac80211)
Core components of the Linux wireless stack, bridging wireless drivers with higher-level networking subsystems.
We assist customers with debugging complex wireless issues, implementing custom features, and optimizing vendor-specific Wi-Fi behavior within upstream-compatible frameworks.
Linux Networking Stack
The Linux networking stack includes critical components such as network device drivers, netfilter, and TCP/IP.
Mandelbit works on extending and customizing networking subsystems, developing new kernel modules, and integrating advanced packet processing features while maintaining upstream compatibility.
OpenVPN
An industry-standard VPN solution used for secure site-to-site and remote-access deployments.
As core contributors, we help customers design, implement, and upstream new features for both OpenVPN 2.x and 3.x, ensuring long-term maintainability and community acceptance.
ovpn (Data Channel Offload)
A Linux kernel module designed to improve OpenVPN performance by moving data processing to kernel space. Included in the mainline Linux kernel since version 6.16.
As main authors of this module, Mandelbit supports customers in deploying, configuring, and extending ovpn for production use cases.
OpenWrt
A minimalist Linux distribution optimized for networking devices such as routers, gateways, and switches.
We help customers build and maintain customized OpenWrt-based firmwares, integrating proprietary components while staying aligned with upstream releases.
working upstream
Contributing upstream is a key part of our approach.
We support customers through the full upstreaming process: from patch preparation and review to community interaction and long-term maintenance after acceptance.
This reduces fragmentation, improves sustainability, and ensures that customer-specific changes do not become long-term liabilities.
related work
Our open-source activity is closely tied to real-world projects and commercial products.
Explore how this experience translates into production systems in our case studies.