mgsimon

Pretty Permalinks requires outofthebox the module mod_rewrite. This module is a workaround to use pretty permalinks without any rewrite rule. The errorhandling – customized errorpage – will be used to resolve pretty permalinks. mg404Rewrite-Modul sends HTTP-Header-Code depending on the request. 
If you have any posts to permalinks, you can try to activate PostProxy to resolve this issue (configurations / misc).
<h3>Licence</h3>
GPL (http://www.gnu.org/copyleft/gpl.html)

mg404Rewrite

This module is a workaround to use pretty permalinks without any rewrite rule.

antonioandra.de

WP htaccess Control should now really be called WP htaccess and Rewrite Control. It provides an interface to customize the htaccess file generated by WordPress but also its permalinks (author, category, archives, pagination and custom taxonomies). Have a look at the screenshot for a clearer idea of the available options.
Features:
<ul>
<li>Customizing the htaccess file generated by WordPress;</li>
<li>Removing any custom taxonomy’s slug base from permalinks;</li>
<li>Removing the category base from permalinks;</li>
<li>Removing the author base from permalinks;</li>
<li>Customizing the Author Permalink Base;</li>
<li>Customizing Paginated Permalinks (translate the “page” word on permalinks to your own language);</li>
<li>Customization (and canonization) of the Search Permalink Base;</li>
<li>Creation of Category, Author, Tag and Custom Taxonomy based archives (ex: “http://your-site.com/category/stories/2010/12”, “http://your-site.com/author/admin/2010/12/page/2” and “http://your-site.com/tag/wordpress/2010/12”), this will also work if you’ve removed the base slug;</li>
<li>Maintenance mode.</li>
</ul>
Easy to use “Suggested htaccess” rules:
<ul>
<li>Jim Morgan’s htaccess;</li>
<li>Disable directory browsing;</li>
<li>Disable and redirect image hotlinking;</li>
<li>Disable and redirect file hotlinking;</li>
<li>Force canonical url (WWW or non-WWW);</li>
<li>Limit maximum file upload size;</li>
<li>Protect wp-config.php file from access;</li>
<li>Protect .htaccess file from access;</li>
<li>Protect comments.php from spam bots coming from nowhere;</li>
<li>Set 500 error page;</li>
<li>Set 403 error page;</li>
<li>Use mod_gzip if available;</li>
<li>Use mod_deflate if available;</li>
<li>Set admin email on server generated error pages;</li>
<li>Disable ServerSignature on server generated error pages.</li>
</ul>
POT file is included, translations are welcome.
<h3>Known Issues</h3>
I still haven’t tested this under WordPress multisite, issues have however been reported.
<h3>Additional Credit</h3>
Removal of the category base is based on iDope’s WP No Category Base but extended so that it works with category archives (ie.: “http://example.com/my-category/2010/12”).
Search redirection is based on Mark Jaquith’s Nice Search but extended so that it works with custom search base (ie.: “http://example.com/search-base/search-term”).
<h3>Stable Versions</h3>
For WordPress versions above 3.9 use the plugin version 3.4.
For WordPress versions above 3.4 use the plugin version 3.3.
For WordPress versions prior to 3.4 use the plugin version 2.7.2.1.

WP htaccess Control

Interface to customize the permalinks (author, category, archives and pagination) and htaccess file generated by WordPress.

mg404Rewrite vs WP htaccess Control