X/OS Experts in Open Systems was founded in 1994 by UNIX experts with an academic background in computer science and a long and deep experience with systems software, including UNIX kernel development. Since the start of our company we have used Linux internally on all our systems. We joined the Linux kernel development community where we developed and maintained the firewall part of the networking stack (1995-2000). In the first years our primary business was providing technical UNIX expertise to our customers. Over time, UNIX was replaced by Linux in many environments and since then we almost exclusively work on Linux and Open Source projects.

We have given talks and courses about firewalls, software packaging and more at many conferences in Europe and the USA. We also co-organized several not-for-profit technical Linux conferences in Germany and the Netherlands, often acting as the program chair. Having personal contacts with many key people and being an active part of the community, we often can get answers to questions beyond the traditional public support channels.

Besides Linux systems software, including Internet and other networking technologies, security and firewalls, we also focus on other free and Open Source software, ranging from databases like PostgreSQL to mobile app development using state-of-the-art cross-platform tools. And last but not least, started as part of a store automation project, X/OS delivers complete point-of-sale solutions. Our strengths also include strong analytical skills, out-of-the-box thinking, and using tools (or simply writing our own) most others wouldn’t even think of. Our customers range from small businesses to large banks and multinationals, and from local governments to international NGO’s.

Expertise:

• Network security, ranging from implementing the Linux kernel firewall and NAT code to building firewall/VPN appliances, based on custom embedded Linux versions.
• Networking: troubleshooting and analysis, as well as developing custom protocols and API’s.
• Internet of Things and implementing MQTT applications.
• Data transformations: manipulating and converting complex data, ranging from XML, YAML, JSON, and CVS to relational databases like PostgreSQL and SQLite.
• Software development: custom software in many languages, although we love Python the most.
• Free and Open Source Software: we have been in this area all the time, so we know the do’s and don’ts, we can judge software quality and we can advise about legal aspects.
• Open standards: we base our work mostly on open standards, avoiding vendor lock-ins and using Open Source software components as much as possible.