Boone Gorges

Requires WordPress 3.0+ Network Mode.
Allows blog administrators to add multiple users to blogs at a time, using only a list of email addresses. When the specified email address matches an existing account, the account will be added as a user on the blog. Otherwise a new account is created and the new user added with the specified role. Based on DDImportUsers.
The plugin determines username automatically from the email address. For example, the email address bgorges100@example.com will produce the email address bgorges100. For that reason, this plugin works best when used in schools or organizations with official, unique email addresses.
When BuddyPress is installed, the welcome email will also include a link to the new user’s Edit Profile screen.
This plugin was developed for Blogs@Baruch of Baruch College’s Bernard L Schwartz Communication Institute. http://blsciblogs.baruch.cuny.edu

Simple Import Users

Allows blog administrators to add multiple users to blogs at a time.

Jesper van Engelen

Adding multiple categories in WordPress can be a real pain. When you want categories for every country in the world, it is a horrible job to fill out and submit the new category form hundreds of times, especially if you’re adding terms that have a hierarchy!
BulkPress makes this process much easier, by providing you with an easy-to-user interface to add categories (and terms of custom taxonomies) and pages/posts (and posts of custom post types) in bulk, giving you the option to specify a hierarchy in the added posts or terms.
BulkPress can spare you hours of your time, just try and find out for yourself!
<h4>More to come…</h4>
BulkPress will be updated with new functionalities very regularly. What to think of the following features coming to your WordPress installations soon…
<ul>
<li>Mass add users</li>
<li>Specify attributes for the pages you’re creating in bulk, such as the page template</li>
<li>Promoting multiple users to a different role in one go</li>
<li>Much, much more…</li>
</ul>
<h4>Feature requests</h4>
If you have any feature requests for this plugin to allow you to mass manage content more easily, just drop the suggestion in the forums!

BulkPress

It does what it says. "It just works". Would be be great if we could add categories or tags to each post but that's fine.

Tested with Wordpress 5.8 and it works like a charm.

FANTASTIC!!

Add posts, pages, categories and custom post types and taxonomy terms in bulk! Managing vast amounts of content made a walk in the park!

Simple Import Users vs BulkPress