If you are writing a reusable module that you plan to make publicly available, you may want to publish the code of your module on GitHub and register it on Packagist.org catalogue as a Composer-installable package. This is absolutely free.
After you register the package, you will be able to add it as a dependency to your web application as follows (replace the vendor
and package
placeholders with your company and package names, respectively):
php composer.phar require vendor/package
Composer will download and install your module to the vendor
directory, so you will be able to use it as any third-party
module.