hazardcell

A newer version for WP3.0 is in the works. I would have loved to release it on time for the release of 3.0 but I’m having my finals at the moment so it will have to wait until June 2010. Will include single sign-on as well.
This plugin is for WordPress MU
This plugin basically allows you to host blogs on multiple domain names while maintaining one main site.
For example, the main site could be example.com but users will also be able to sign up for blogs on example.net, example.org or any other domain name that you choose to add.
<ul>
<li>All the sites will have the same settings</li>
<li>No extra blogs/tables are created for the additional domain names</li>
<li>All blogs will be viewable on the Site Admin blog list</li>
</ul>
Alternatively, if you would like to request a feature and/or report a bug, please visit the <a href="https://wordpress.org/tags/yet-another-multi-site-manager" rel="ugc">forum</a> or the <a href="https://plugins.trac.wordpress.org/browser/yet-another-multi-site-manager/" rel="nofollow ugc">trac repository</a>. You will have to login with your WordPress.org username and password to access these.
<h3>Known Issues/Limitations</h3>
<ul>
<li>Remote login does not work with this version</li>
<li>Only tested with VHOST installs in root directory</li>
</ul>

Yet Another Multi-Site Manager

Allows blogs to be created on multiple domain names while maintaining only one main site for all domain names.

Unioney

MassPost is the ultimate tool for editors, publishers, and agencies managing multiple WordPress websites. 
Instead of copying content across sites, you can publish a post once and automatically syndicate it to as many target websites as you like.
<h3>Why Choose MassPost?</h3>
<ul>
<li>Publish Once, Share Everywhere – Write your post once and send it to all your websites with a single click. </li>
<li>Keep Your Content Consistent – Categories, tags, featured images, and formatting are preserved across all sites. </li>
<li>Stay Organized – When you delete a post, it’s automatically removed from all connected sites. </li>
<li>Save Time – Edit posts faster with Quick Edit support right from your posts list. </li>
<li>Schedule Ahead – Set a future publish date and it syncs perfectly across all your websites. </li>
<li>Protection Built-In – Your sites communicate securely with password-protected connections. </li>
<li>Only Send What Changed – MassPost is smart enough to skip posts that haven’t been modified, keeping things fast. </li>
<li>Your URLs Stay the Same – Post links (slugs) remain consistent, making it easier for readers to find content. </li>
<li>Content Images Sync – Images embedded in your post content are automatically downloaded and hosted locally on each target site.</li>
</ul>
MassPost streamlines content distribution, keeps your network of sites consistent, and saves countless hours of manual work.
<h3>Requirements</h3>
<ul>
<li>WordPress 6.0 or higher </li>
<li>PHP 7.4 or higher (works with PHP 8.0 → 8.4) </li>
<li>WP-Cron (or real cron) enabled </li>
<li>Standard PHP extensions: cURL, OpenSSL, DOM </li>
<li>512 MB+ PHP memory recommended if running many feeds with AI</li>
</ul>
Best practice for performance 
For the smoothest AI processing and zero-maintenance cron execution, we recommend hosting your WordPress site on <a href="https://ihost.eco" rel="nofollow ugc">ihost</a> WordPress Cloud Hosting. See FAQ Recommended hosting for an ihost-optimised <a href="https://wordpress.org/plugins/masspost/#suggested%20php%20directives" rel="ugc">php.ini</a> template you can copy-and-paste.

MassPost – Post, Share, Send to Several Websites

Publish once, distribute everywhere. MassPost securely pushes WordPress posts, all formats, images, categories etc to multiple sites.

Yet Another Multi-Site Manager vs MassPost – Post, Share, Send to Several Websites