ASP.NET Core is a lean and composable framework for building web and cloud applications. ASP.NET Core is fully open source and available on GitHub. ASP.NET Core is available on Windows, Mac, and Linux.
Have you built something significant with it you can point to? This is not snark - I'd really love to hear about it.
I don't mind Java, I generally like using Java 8, but I would happily be writing C# instead if I could run it as easy in as many places. The syntactic sugar, Linq, the latest MVC framework, etc- are generally much faster to get moving in and don't require the configuration hell you can run into w/ Java.
However, as a guy who ALSO maintains the servers and deployment process for the things we build, I'll continue avoiding .NET until it can be built, archived, and deployed as easily as we do our Java based applications. I don't think I could even maintain a Windows Server now if I had to.
.Net core runs on linux, so you don't even need a windows server.
If you're talking about Ant, Maven, Tomcat, etc for Java deployment, it's been about 5 years since I've had to use that, but I'd say Octopus is a much better process than that.
It was this guy that gave the talk, he has a blog with lots of information about his experience with Octopus. A few of the quirks I encountered when getting everything set up with our company were resolved by reading his blog: http://ianpaullin.com/category/octopus-deploy/
.NET Core has almost all of the features of the full .NET framework and C# is a pleasure to work with. My team is very productive and we are able to iterate very quickly. Since it is a compiled language, most errors are caught at build time.
Deploying is another pain point. You have to install the framework on Linux and ship all of your dependencies. They make it easy with the `dotnet publish` command. I'm excited for .NET Native which will package everything into a binary.
I think that PostgreSQL has a similar open source story. There's `Npgsql` for a driver and `Npgsql.EntityFrameworkCore.PostgreSQL` for the Entity Framework implementation.
It took some work, but I like that Entity Framework Core allows for it's implementations to be done by the Open Source community. In MySQL's case, we've added lots of MySQL-specific optimizations to the Entity Framework implementation after getting feedback from the community. The new open Microsoft development approach here is great.
Full disclosure: primarily a Java dev but have worked in PHP, and to a lesser degree python as well. Oh, and I now work full time on .Net.