DCoda

This plugin is only supported on PHP 5.2 or greater.
 
ExportReaders easily allows you to export your users details for use elsewhere. 
Just select the roles you with to export and set the criteria to select the commenters and download its that simple. 

If you are having trouble and cannot find the answers in the <a href="http://exportreaders.dcoda.co.uk/help/faq/" rel="nofollow ugc">FAQ</a> you can post your support questions to the <a href="https://wordpress.org/tags/export-readers" rel="ugc">WordPress Support Forum</a>
If you find ExportReaders useful please rate it at <a href="https://wordpress.org/extend/plugins/export-readers/" rel="ugc">wordpress.org</a> and please consider making a <a href="http://exportreaders.dcoda.co.uk/donate/" rel="nofollow ugc">donation</a> to help us set aside more hours to maintain ExportReaders
ExportReaders is written by <a href='http://dcoda.co.uk' rel="nofollow ugc">dcoda</a>
You can check out our other plugins <a href="https://profiles.wordpress.org/users/dcoda/" rel="nofollow ugc">here</a>
If you require a custom plugin you can contact us <a href="http://dcoda.co.uk/contact/" rel="nofollow ugc">here</a> and maybe we could write it for you.
<h3>Copyright</h3>
(c) Copyright DCoda Limited, 2007 -, All Rights Reserved.
This code is released under the GPL license version 2, available here:
<a href="http://www.gnu.org/licenses/gpl.txt" rel="nofollow ugc">http://www.gnu.org/licenses/gpl.txt</a>
There are so many possibly configurations of installation the plugin can be installed on we limit testing to a PHP 5.2+ Linux platform running the latest version of WordPress at the time of release but it is released WITHOUT ANY WARRANTY; 
 without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

ExportReaders

Selectively export all your reader details ( users and commenters )

CPK Web Solutions

Most WP features are fully supported:
<ul>
<li>More than 50000 lines can be imported/exported (the only limit is your server)</li>
<li>Posts, pages, and custom post types</li>
<li>Tags, categories, and custom taxonomies </li>
<li>Custom fields (simple and complex)</li>
<li>Thumbnails</li>
<li>Flexible filter system to easily control which fields export</li>
<li>Simple User Interface (if you know Excel or another spreadsheet program, you will find this plugin quite easy) 
The plugin should now be usable with most plugins that are fully WordPress compliant.</li>
<li>Shortcode to allow frontend download by your visitors if you choose</li>
</ul>
Learn more <a href='http://cpkwebsolutions.com/wp-csv' rel="nofollow ugc">here</a> and read the full documentation including a <a href='http://cpkwebsolutions.com/plugins/wp-csv/quick-start-guide/' rel="nofollow ugc">quick start guide</a> and a description of all the kinds of fields you’ll see.
SUPPORT
We no longer provide any free support for the following <a href='http://cpkwebsolutions.com/plugins/wp-csv/support-and-donations' rel="nofollow ugc">reasons</a>.
If you see value in the plugin, <a href='http://cpkwebsolutions.com/donate' rel="nofollow ugc">support</a> it!

WP CSV

A powerful, yet simple, CSV importer and exporter for Wordpress posts, pages, and custom post types.

ExportReaders vs WP CSV