At FOSDEM 2023 [1] in Brussels, FOMO (the fear of missing out) was the buzz word, not only for people who did not make it to the event, but also for the conference attendees. Although the event in the Belgian capital attracted a slightly smaller audience than in years prior to the COVID-19 pandemic, visitors repeatedly turned to live-streams because the conference rooms hosting popular topics quickly filled up.

The First Instance

A particularly large number of comments and FOMO statements appeared on Mastodon, where the #Fosdem topic was very popular for some time. Thanks to Elon Musk, Mastodon is currently experiencing a flurry of activity. GitHub developer Kris Nóva, who was unexpectedly dragged into the Mastodon universe last year, vividly described how lively things were. Her plan to build a separate Mastodon instance, Hachyderm [2], for friends took off with thousands of new users gradually migrating to the instance.

Upon reaching 30,000 accounts, the quite powerful hardware in Nóva's basement broke down. It was time to move the service to a cloud, and Nóva chose German provider Hetzner. The data protection regulations (hashtag #GDPRforever) were probably also a decisive factor in the move, along with Nóva and her supporting developers needing to field some of the inevitable questions about the general handling of a privately managed Twitter alternative. Nóva pointed out in her keynote that this is where the pitfalls lurk. If you are thinking about setting up a Mastodon instance, you will definitely want to watch the video [3].

Not only does a Mastodon instance above a certain size need a reliable technical infrastructure, it also faces legal pitfalls. For example, instance operators need to keep the massive amounts of private data secure, which means having volunteers or paid staff moderate the posts. Operators also need to be careful about which other Mastodon instances from the Fediverse they integrate into their platform and which ones they don't. In addition, they also need to consider how to handle corporate accounts [4]. Last but not least, operating a project like this can quickly consume finances. According to Nóva, technical operations of her instance alone incur monthly costs of around EUR1,000.

The solution, according to Nóva, is the newly established Nivenly Foundation [5]. The instance's operators will be looking to collect membership fees through the foundation in the future to refinance operations. This seems to make sense: Where selling user data and advertising cannot be the business model, you need to find alternatives to operate a volunteer project sustainably.

New Energy

Sustainability also played a central role at FOSDEM in another context: the avoidance of fossil fuels and the battle against climate change. The organizers assigned a separate energy track to this pressing problem, along with space in the main stage program.

Felix Rehmann's research project at the Technical University of Berlin, for example, analyzed the software of 180 research projects that aim to determine, control, or optimize a building's energy requirements. Emissions from buildings are some of the biggest drivers of climate change. The results are exciting.

While most of the 180 projects use at least one open source component, only a few of the mostly publicly funded projects (about 3%) plan to release their software. The reasons range from ethical to technical to cultural concerns. Often, projects simply expire after some time, and the software becomes orphaned. The focus on users is often missing, the licensing situation remains unclear, or the developers are simply afraid of embarrassing themselves. Some researchers also keep their software proprietary for commercial reasons. Despite all these problems, Rehmann is convinced that it would be better to use more open source software in the field, such as CAD programs or simulation software for renovations.

Space, Road, and Data Center

Even NASA made it to FOSDEM (Figure 1). NASA is also looking to use its data to help in the fight against climate change, for example, in the scope of the POWER project [6]. Astronomer Steve Crawford explained that the US space agency is currently opening up to open science, increasingly adopting open APIs, and maintaining open datasets and open access models. However, this is not entirely voluntary. According to a US government decision, starting in 2026 all publicly funded research must also be immediately available to the general public.

Figure 1: Even a NASA astronomer made it to FOSDEM and spoke about open source in space, among other things.

Another topic at the conference dealt with electric cars. Vehicle-to-Grid (V2G) pursues the idea of turning electric car users into decentralized electricity producers. The idea is for electric car users to feed the electricity generated from wind or solar energy for their electric vehicle into the power grid in exchange for money. Products to help people do this are available from commercial providers, but they usually look to sell a complete solution. V2G Liberty [7] wants to offer an alternative. Nicolas Höning presented this project in his keynote, along with the setup that was developed. This includes Home Assistant [8], Nextcloud [9], and the LF Energy Foundation-funded FlexMeasures [10], among others.

Höning also explained the potential pitfalls and gave examples of best practices. One thing is clear: The less owners move their cars, the more electricity they can generate. In the ideal case, up to EU10 per day can be earned with vehicles converted in this way. The project is still in its infancy, but that has never deterred open source enthusiasts.

Finally, Parul Singh and Kaiyi Liu presented CO2-sensitive scheduling for Kubernetes. Admins feed the rules for this to the container platform in the usual declarative style. Kubernetes Efficient Power Level Exporter (Kepler) [11] lets you move pods and their workloads automatically to other areas of the world based on their power consumption. Ideally, CO2-neutral electricity will then be used there. The containers' energy requirements are determined by eBPF programs, although obtaining the information on the types of electricity is probably not entirely trivial and sometimes also costs money. A software development kit for the Green Software Foundation is also expected to emerge from the project in the end.