AMSTERDAM — There’s plenty of money in the global economy. And a big part of the economy runs on software. And software is mostly open source.We’ve heard that before.However, many companies still fail to invest in open source projects, despite the benefits they offer. What is the value of open source? It’s worth $8.8 trillion, a total that reflects what it would cost to create software from scratch if it weren’t freely available, according to Harvard University.Too often, the burden to support open source projects comes down to individuals like Daniel Stenberg, the technologist who created curl, the command line tool and library for transferring data with URLs.Stenberg runs the curl project from his home office in Sweden. The project started in 1996 with 100 lines of code. Today, it has 180,000 lines of code, generated by about 1,400 authors. In total, 30,500 people have helped in some way with the project.Curl’s presence is legendary. It is installed in over 20 billion instances. Phones, cars, tablets, game consoles, servers, desktop operating systems — you name it, curl is there.Stenberg keynoted here on Monday at the Open Source Summit Europe, with a few stories about what it can be like to maintain a project with such impact.The Challenges Facing MaintainersStenberg puts his project in the same realm as the millions of other open source projects that individuals run.“There are somewhere around 11 million open source projects, and millions of open source developers,” he said in his speech on Monday. “And maintaining is a lot of things, right? I tend to say that I do a lot of things as a maintainer, and in a small project, most of these tasks are mine.”It’s like the world’s IT infrastructure is an elephant, balancing on a beach ball that ants hold up, an image that Stenberg showed in his keynote presentation. The weight on individual open source developers is just tremendous.