Ryan Welcher

This is a simple plugin that helps to clean up the admin side of WordPress by only showing the currently logged in user’s content the Post/Page/Media pages.
For the Media list, you can provide a list of user ID’s who’s Media will also be available to logged in users. It is highly recommended to create a user for this purpose.
Credits
This plugin was inspired by an article by <a href="http://premium.wpmudev.org/blog/author/pollyplummer/" rel="nofollow ugc">Sarah Gooding</a> on <a href="http://premium.wpmudev.org/blog/how-to-limit-the-wordpres-posts-screen-to-only-show-authors-their-own-posts/" rel="nofollow ugc">wpmudev</a> and uses portions of that code. Please see the source code for further details.

Restrict User Content

Limits Post/Pages/Media admin screens to only display the current user's content. Media can be shared by providing an ID list.

Floate Design

Ghostwriter overrides WordPress’s author pages and feeds to emulate the full functionality provided to WordPress users. Ghostwriter was developed by Floate in Melbourne. Just north of the river.
<h3>When to use Ghostwriter</h3>
Ghostwriter is best used for a blog written by multiple staff members but with a single person performing data entry.
Ghostwriter works when the writing and approval process operates outside of the WordPress dashboard. If approval is done within the dashboard, setting up users as contributors may be better.
<h3>Copyright And Warranty</h3>
Copyright © 2012 Floate Design Partners
This software is provided for free, as is, under the GPL v2

GhostWriter

Ghostwriter overrides WordPress’s author pages and feeds to emulate the full functionality provided to WordPress users.

Restrict User Content vs GhostWriter