We're using jsonnet for our systems and they have absolutely nothing to do with k8s. I'm not sure it's true to say it has ever gained much traction. It's just

We're using jsonnet for our systems and they have absolutely nothing to do with k8s. I'm not sure it's true to say it has ever gained much traction. It's just a niche case for complex configuration, and isn't the most publicised tool. It does precisely what we need with zero fuss, cross platform and cross _language_ (we've embedded it in C++, .NET, and JVM executables). We can use the resulting json config with a vast array of tools that simply don't exist for the alternatives such toml/yaml/hocon/ini whatever. In fact we tried to get HOCON working for non-JVM languages but there was always some edge case.