This plugin allows the use of URLs as an SCM plugin

This is an SCM plugin for Hudson. While URLs are not actually a proper SCM, the two main behaviors of an SCM are supported - checkout and polling. Polling is accomplished by checking the last-modified property of the URL. Checkout is accomplished by copying the content of the URL into the workspace as a file.  The file is given the same name as the final filename component of the URL.  URLs without a filename component cannot be used at this time.  

This does duplicate some of what the URL Trigger plugin does.

Benefits this plugin over the URL Trigger are:
1. You can choose your own polling schedule via the SCM Polling trigger.
2. Less resource intensive polling mechanism, since checking last-modified requires few bytes to transfer, regardless of the amount of data in the URL.

Benefits of URL Trigger over this plugin:
1. Hudson only supports one SCM plugin per project. If you want to trigger an SCM checkout via a URL, then URL Trigger is a better choice.
2. The last-modified property of a URL is not the right trigger for your builds, instead you need the content of the URL to change to trigger a build.