Open Source is fundamental for Palark's very existence: our services wouldn't be possible without all the great projects, such as Kubernetes and Linux. This article is not so technical, but we want to share our knowledge on how the beautiful idea of FOSS works in practice, i.e. real business.
Their product offers many more features (and more complex ones) than the other services you mentioned. And they also took the time to provide a commercial product, with paid support, integrations…
This is key for companies, as it makes it easier to be productive, plus the SLAs give some peace of mind too.