[bebop]

Not the parent, but C# and Java are very similar in their feature set. One thing that I find interesting about the respective communities is, Java tends to develop JSR's where a standard is worked on by multiple vendors and published essentially as an interface. Many vendors then provide an implementation of the interface.

In C# Microsoft often provides the most popular tooling for common problems. For instance, in web development, Microsoft publishes ASP.net and Entity Framework. In Java there is Jax-rs (JSR 339) and JPA (JSR 317).

So depending on your preference for a strong centralized environment provided by a single vendor, or a decentralized standards based solution with many vendors, you might lean towards Java or C#.