Justin Tadlock

X3P0: Authors is a block that lets you display a simple list of post authors for your site. This is especially useful if you’re coming over from using a classic WordPress theme and need a block that’s similar to the old <code>wp_list_authors()</code> template tag.
Aside from the full array of normal block design tools, the block lets you choose from several options:
<ul>
<li>Number: Decide the number of authors to list.</li>
<li>Order By: Choose from a variety of fields to order the list by.</li>
<li>Order: Whether to display the list in ascending or descending order.</li>
<li>Has Published Posts: Whether to only show authors who have published posts.</li>
<li>Show Feed Link: Whether to show an icon linked to the author’s RSS feed.</li>
<li>Show Post Count: Whether to display the author’s published post count.</li>
</ul>
You can find the full source code for this plugin via its <a href="https://github.com/x3p0-dev/x3p0-authors" rel="nofollow ugc">GitHub repository</a>.

Authors List Block

A customizable authors list block that lets you showcase post authors, their feed links, and post counts.

mattdu

This plugin uses the custom taxonomy features of WordPress to create “bylines” — essentially, tags representing authors who contributed to a post. The differentiating feature of this plugin is that it should not require any modifications to your theme files (assuming it is already displaying the post author).
This plugin would be useful for publishing situations where the majority of your content is from contributors who you don’t necessarily want to have access to your back-end. It still conveys the appearance that the authors are members of the site (it provides a built-in archive page for each Byline). If your theme displays tag descriptions, you could use the Byline description field to identify guests vs. “staff” writers or provide other author information.
You can see an example of this plugin at work at http://thedailycougar.com

Byline

The Byline plugin is simple and suitable for multi-author WordPress sites.

Best For Multi Author

Solves the co/multi-author problem without modifying the theme. Uses a custom taxonomy, "Byline," that replaces the Display Author.

Authors List Block vs Byline