Adding new datasources to Gnowsis is easy, a new datasource needs to define at minimum three classes: 

 1. A class implementing Aperture:DataSourceFactory
 1. A class implementing Aperture:CrawlerFactory a
 1. A class extending Gnowsis:ConfigPanel 

Pack these classes up in a jar, write a sensible manifest and put them in ~/.gnowsis-beta/datasources

An example MANIFEST.MF: 

{{{
Manifest-Version: 1.0
Created-By: 1.4.2_09 (Apple Computer, Inc.)
Gnowsis-DS-CrawlerFactory: org.gnowsis.data.datasource.rss.RSSCrawlerFactory
Gnowsis-DS-DataSourceFactory: org.gnowsis.data.datasource.rss.RSSDataSourceFactory
Gnowsis-DS-ConfigPanel: org.gnowsis.data.datasource.rss.RSSConfigPanel
Gnowsis-DS-Icon: /org/gnowsis/data/datasource/rss/rssicon.png
Gnowsis-DS-Label: RSS Datasource
Gnowsis-DS-URI: http://example.org/RSSDatasource
Gnowsis-DS-Desc: A datasource for crawling RSS feeds.
}}}

Note that blank lines are not allowed.