Gianluigi Filippelli

<a href="https://wordpress.org/plugins/co-authors-plus/" rel="ugc">Co-Authors Plus</a> is one of the most useful plugin for multiple authors blogs. This plugin add a widget to add users’ avatars to post also for guest authors and for posts with multiple authors. 
You can also add avatars with a shordcode [blog-post-coauthors]. 
The plugin add also a slider in order to show user’s profile. If you want change the style, you can modify blog-spoiler.css file in the plugin folder.

Co-Authors Widget

The plugin add a widget and a shortcode in order to show authors of an article. It is compatible with Co-Authors Plus.

leticia

This very simple plugin allows multiple authors to be assigned to a Post or Page.
In admin panel, when you add or edit a post or page you can:
<ul>
<li>
specify additional authors, by selecting and adding them in the “Co-authors” panel. (See Screenshots #1)
</li>
<li>
put the shortcode “[sp-authors]” to display the list of co author’s links separated by comma.
</li>
</ul>
When the post/page is displayed to user:
<ul>
<li>you can see the list using the shortcode that can be added in the add post page</li>
</ul>
In any template:
<ul>
<li>
you can user the template-tag “sp_authors_display” to show the list of coauthors “display_name”, separated by comma
</li>
<li>
you can user the template-tag “sp_authors_photos_display” to show the list of coauthors avatars
</li>
</ul>
In search for author functionality:
<ul>
<li>the search take in care all authors, no just the user who write the post/page</li>
</ul>

SP Authors

This very simple plugin allows multiple authors to be assigned to a Post or Page.

Co-Authors Widget vs SP Authors