We encourage you to try the Meso language yourself. To execute the Meso source code, you need the Meso runtime, which itself is written in Java at the moment:
You do not need a separate Meso compiler. The runtime has a built-in compiler that compiles the source code on-the-fly before execution. Note that it is not just an interpreter. The built-in compiler performs static type checking on the entire source code before generating target code for the runtime, much like a conventional compiler.
We intentionally put the compiler and the runtime system together so that a Meso program will be compiled from source code every time upon execution. We believe this suits better for Internet applications than pre-compiling them, since remote objects and data types might unilaterally change their definitions at any time. Performing type checking before execution can ensure that the program is still "compatible" with the current Internet environment. We can use various caching techniques to speed up the startup time.