DCoda

This plugin is only supported on PHP 5.2 or greater.
 
MembersBlog easily allows you to lock down your blog to members only. 
Unauthenticated visitors who try to view the blog content will be forced to the login page , or presented with an browser login prompt if they try to view the feed.
When the blog and feed are locked down to subscribe to a feed using a feed reader a username and password must be supplied in the url:
<pre><code>http://{username}:{password}@{feed url}
</code></pre>

If you are having trouble and cannot find the answers in the <a href="http://membersblog.dcoda.co.uk/help/faq/" rel="nofollow ugc">FAQ</a> you can post your support questions to the <a href="https://wordpress.org/tags/members-blog" rel="ugc">WordPress Support Forum</a>
If you find MembersBlog useful please rate it at <a href="https://wordpress.org/extend/plugins/members-blog/" rel="ugc">wordpress.org</a> and please consider making a <a href="http://membersblog.dcoda.co.uk/donate/" rel="nofollow ugc">donation</a> to help us set aside more hours to maintain MembersBlog
MembersBlog 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.

MembersBlog

Lock down all your posts and pages so only members can access them

Sherpah_

The Safe Private Plugin set up a members-only area on your WordPress and protect your content, pages and resources from public access. 
Only registered users will be able to browse your site. The plugin will redirect all others users to the login page of your blog. 
Deny access to unregistered users, perfect for a private website, helpful during a blog maintenance and useful for developers…
<ul>
<li>Membrers-only area</li>
<li>Members only feed</li>
<li>No template modifications</li>
<li>Fast, Safe and secure…</li>
</ul>
Author Plugin link page: <a href="http://www.sherpah.net/wordpress/plugin-safe-private/" rel="nofollow ugc">Safe Private</a>

Safe Private

A Private Wordpress, a Members-only Website, helpful during a site maintenance and useful for developers...

MembersBlog vs Safe Private