## Chapter 5. Common tasks

This section describes main targets types that Boost.Build supports of-of-the-box. Unless otherwise noted, all mentioned main target rules have the common signature, described in the section called “Declaring Targets”.

## Programs

Programs are created using the `exe` rule, which follows the common syntax. For example:

    exe hello : hello.cpp some_library.lib /some_project//library
              : <threading>multi
              ;

This will create an executable file from the sources -- in this case, one C++ file, one library file present in the same directory, and another library that is created by Boost.Build. Generally, sources can include C and C++ files, object files and libraries. Boost.Build will automatically try to convert targets of other types.

| Tip
On Windows, if an application uses dynamic libraries, and both the application and the libraries are built by Boost.Build, its not possible to immediately run the application, because the `PATH` environment variable should include the path to the libraries. It means you have to either add the paths manually, or place the application and the libraries to the same directory. See the section called “Installing”.