DynRes uses an integrated web server to serve a resourcepack directly from the install directory. It also modifies the server to specify that pack as the default (overwrites resource-pack and resource-pack-sha1 in server.properties) You can configure the port for the web server, the file to host and whether to provide a hash  in the config.

To use this mod on your server you need to place your resource pack in the configured place (default: server/resources.zip) and change baseLink in the config to your public address (what players will enter)

This mod is only required on your server. If added to a client the only thing it will do is log some information about server connections