This project aims to implement "The Computer Language Benchmarks Game" in Vala.

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#, modified to better fit the GObject type system.

From Vala FAQ:

How does the performance of Vala applications compare to other applications?
The performance should be pretty similar to GObject/C-based code as there is no Vala-specific runtime library/environment that needs to be loaded. The C compiler can also apply the same optimizations on Vala-generated C code and plain GObject/C code. The Vala compiler uses reference counting in more places than most GObject/C-based applications do. However, Vala allows to fine-tune that easily in performance-critical sections with the weak modifier.
If you want to help this project please begin to read HowTo and if you want more informations, look at the documents.

All the benchmarks are not complete but you can see partial results on the BenchResults page.