.NET Orleans
I spent some time learning dotnet core this year and with the slow-grind progress Microsoft has made it really does look like the technology stack might start to replace Java, Go, Rails, NodeJS, over the next decade. You can really feel Microsoft's experience in language development and enterprise software development coming together to provide better ecosystem ergonomics than other frameworks and toolchains.Specifically I'm talking about tools like LINQ, dotnet core libraries, VS and VS Code integration, and the standard library and common library packages.I still think it has a long way to go but its still a huge potential upside, which is to say nothing of how its coming to dominate the games industry as well.