The Whiley Compiler (WyC) is one component of the larger Whiley Build Tool. When you run wy build on the command line, you are running the build tool which, in turn, runs the Whiley Compiler (amongst other things). The compiler is responsible for turning whiley source files into wyil intermediate language files. The compiler doesn't generate JavaScript or other binary code, as these aspects are handled by other components (e.g. the Whiley JavaScript backend).
The easiest way to get started with Whiley is by running it in your web-browser on whileylabs.com. To run Whiley from the command-line (e.g. wy build), see instructions for installing the Whiley Build Tool. You can find more information about Whiley at whiley.org.
When making a contribution to the Whiley project, you will need to first sign-off the developers certificate of origin. Please see the CONTRIBUTORS file for more details.
An overview of the compiler's architecture is provided in ARCHITECTURE.md.