This is a gem that allows you the developer to filter out jobs in job listings that you wouldn't be interested in, and allows job lister's to exclude jobs from developers.  So and add that reads "2 years front end experience required" would not be show up for a developer who has 2 years backednd experience.  Jobs would be specified in a concise language with named variables and stuff.  The gem would be able to parse emails and adds and convert them into this concise syntax.