You have a choice between three popular Erlang web servers:
Either Mochiweb, Webmachine, Cowboy, or Yaws is recommended for production use. Whichever one you choose is up to personal preference, but Inets is not recommended for running in production because it does not yet include content-caching/expiration headers, which can cause slow loadtimes.
These packages were generated from Nitrogen source code by running make package_inets, make package_cowboy, make package_mochiweb, make package_webmachine and make package_yaws.
Alternatively, if you plan on contributing to the Nitrogen source code, you can download the source tree from GitHub.