|GObject Reference Manual|
From the Vala homepage itself: “Vala is a new programming language that aims to bring modern programming language features to GNOME developers without imposing any additional runtime requirements and without using a different ABI compared to applications and libraries written in C.”
The syntax of Vala is similar to C#. The available compiler translates Vala into GObject C code. It can also compile non-GObject C, using plain C API.