Simon Wheatley

A plugin providing template tags to list all active (or inactive) authors in the WordPress installation.
<pre><code><?php list_active_authors( 'days=30&include_protected_posts=0' ); ?> Will list all the authors active in the last 30 days, not counting password protected posts as "activity". Both parameters are optional.

<?php list_inactive_authors( 'days=30&include_protected_posts=0' ); ?> Will list all the authors NOT active in the last 30 days, counting password protected posts as "activity". Again, both parameters are optional.
</code></pre>
If “days” are not provided the tags default to the last 30 days. 
If “include_protected_posts” is not specified, the tags default to not including password protected posts.
The HTML output is fairly heavily classed, but if you need to adapt it you can. Create a directory in your theme called “view”, and a directory within that one called “author-listings”. Then copy the template files <code>view/author-listings/active-authors-list.php</code> and/or <code>view/author-listings/inactive-authors-list.php</code> from the plugin directory into your theme directory and amend as you need. If these files exist in these directories in your theme they will override the ones in the plugin directory. This is good because it means that when you update the plugin you can simply overwrite the old plugin directory as you haven’t changed any files in it. All hail <a href="http://urbangiraffe.com/" rel="nofollow ugc">John Godley</a> for the code which allows this magic to happen. Can hook into the <a href="https://wordpress.org/extend/plugins/user-photo/" rel="ugc">User Photo plugin</a> to display the author photos.
Plugin initially produced on behalf of <a href="http://www.puffbox.com" rel="nofollow ugc">Puffbox</a>.
Is this plugin lacking a feature you want? I’m happy to accept offers of feature sponsorship: <a href="http://www.simonwheatley.co.uk/contact-me/" rel="nofollow ugc">contact me</a> and we can discuss your ideas.
Any issues: <a href="http://www.simonwheatley.co.uk/contact-me/" rel="nofollow ugc">contact me</a>.

Author Listing

Allows listing of authors who are active or inactive within a defined recent period of time.

Debashish

Author Spotlight widget displays the profile of the author(s) with Social links (example: Twitter, Facebook) and his/her profile picture or Gravatar on any post or page that has an Author. The widget automatically detects the current author(s) of the displayed post or page; just drag and drop the widget on your sidebar and you are done.
To display a custom photograph with the Author’s Profile you may install the <a href="https://wordpress.org/extend/plugins/user-photo/" title="User Photo WordPress plugin" rel="ugc">User Photo</a>. In absence of this plugin the widget will fall-back to displaying the Gravatar associated with the user. If your posts have multiple authors you may use the <a href="https://wordpress.org/extend/plugins/co-authors-plus/" title="Co-Authors Plus WordPress plugin" rel="ugc">Co-Authors Plus</a>, the Author Spotlight will then display all the author profiles one below another for such post/page.
Note that installing the User Photo or Co-Author plugin is purely optional, this widget will work fine without them as well.
If you face any issues with the plugin or have any suggestion/feature requests please do so <a href="https://wordpress.org/tags/author-profile" title="Author Spotlight plugin support forum" rel="ugc">at the support forum</a>.

Author Spotlight (Widget)

A Sidebar widget to display the Author(s) profile on any Page or Post along with Social web links.

Author Listing vs Author Spotlight (Widget)