tj2point0

Taxonomic SEO Permalinks is a simple plugin that allows you to create SEO urls based on custom taxonomies in WordPress. I personally wanted to use custom taxonomies in URLs just like built-in taxonomies like category. WordPress does support some options that helps in ‘rewrite’ of permalinks, while creating custom taxonomies. However, I found this thing is not actually working, as I tried and tested.
So I have created this plugin to fix this issue. This plugin does two major works. First, it modifies links to posts at all the places in blog and second, it helps in parsing the URLs. If you did not understand what I just said, leave it and read below.
Let me explain you with the help of an example, what we are trying to achieve with this plugin.
Consider a university website want to build a website for announcing results. The results are announced every six months (summer 2010, winter 2010, …) for various courses (BSc, BTech, …) and for various semesters (final year, second semester, …).
So we can create three custom taxonomies viz. Season, Course and Semester. What we want is SEO url with the help of custom WordPress taxonomies that will look like:
<pre><code>http://example.com/winter-2010/bsc/final-year/list-of-passed-candidates
</code></pre>
Which you can set in your regular permalink structure options just like
<pre><code>/%season%/%course%/%semester%/%postname%/
</code></pre>
NOTE: Currently this plugin do not help you to create custom taxonomies. You will need to use another plugin to create custom taxonomies.

Taxonomic SEO Permalink

This plugin helps you to set your permalinks by using custom taxonomies just like you use %category% or %postname% in your permalink structure.

M.Code

Jan Fabry

Understand how rewrite rules work could be userful. 
Natively on WordPress you can’t analyze what’s working / not working regarding your urls. 
Through this interface you will be able to analyze every single url and see what’s matching.
Warning 
This tool will not change / add any rules for you it’s only an analyzer
<h4>Main features:</h4>
<ul>
<li>Live URL Analyzer</li>
<li>Highlight parameters</li>
<li>AJAX Permalinks refresh button</li>
<li>Change UI (Light / Dark)</li>
</ul>

Url Rewrite Analyzer

See clearly and understand how WordPress rewrite rules work within a simple and clean interface

Taxonomic SEO Permalink vs Url Rewrite Analyzer