mortenf

This plugin monitors a <a href="http://www.intertwingly.net/code/venus/" title="Planet Venus" rel="nofollow ugc">Planet Venus</a> cache 
directory and syndicates new entries as posts. 
It automagically creates users and categories as necessary.
The plugin was originally released on <a href="http://www.wasab.dk/morten/blog/archives/2006/10/22/wp-venus" title="WP: Venus" rel="nofollow ugc">Binary Relations</a> by <a href="http://www.wasab.dk/morten/" rel="nofollow ugc">Morten Frederiksen</a>.
<h3>Maintenance</h3>
When running correctly, the WordPress Venus plugin automatically adds users, categories and posts as needed, based on the information in the Atom entry files from the Venus cache directory. Each Atom entry file is only parsed when created or updated, so you may update existing posts, categories and users in WordPress as needed, in case something looks odd — your changes will not be overwritten unless the entry file is updated. If you delete a post, the plugin will try to remove the corresponding Atom entry file in the cache directory as well. For that to work, the web server process needs write permission to the cache directory.
If you find that the same users suddenly appears more than once in the WordPress user system (this may happen if the same user posts from different sources), you can use the Venus options screen to merge the two into one. The merge will be preserved for future arriving posts. This is accomplished by storing unique IDs for each user, as can be seen and maintained on the user edit screen.
Since the plugin scans the Venus cache directory to look for updates, you will likely find, that it slows down after a while. You may want to clean out the cache directory every now and then, possibly through the use of a cron job, and Venus’s -x switch.
<h3>License</h3>
Copyright (c) 2006-2009 Morten Høybye Frederiksen <a href="mailto:morten@wasab.dk" rel="nofollow ugc">morten@wasab.dk</a>
Permission to use, copy, modify, and distribute this software for any 
purpose with or without fee is hereby granted, provided that the above 
copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED “AS IS” AND THE AUTHOR DISCLAIMS ALL WARRANTIES 
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

WP-Venus

A plugin for running a syndication planet using Planet Venus through its cache directory, with complete support for multi author feeds and categories.

fitztrev

With the Subscribe-Remind plugin, some text will automatically be placed at the end of each of your posts inviting your readers to subscribe to your RSS feed or follow you on Twitter. It’s an unobtrusive and effective way to turn visitors into subscribers.
<h3>Importance</h3>
With more and more people using RSS readers to get content, it’s important that your blog’s feed be easily accessible. By increasing your syndication audience, your readers will be exposed to much more of your content.

Subscribe-Remind

Subscribe Remind will add a brief message at the bottom of each post inviting users to subscribe to your RSS feed or follow you on Twitter.

WP-Venus vs Subscribe-Remind