highimpacttech

This plugin adds .html (or any extension) to your WordPress page and category urls.
You can change the extension from Plugin Setting page.

Custom category and page extensions

Add any ".extension" to WordPress category and page urls.

David Cramer

Routed Actions is a development tool that allows you to create a URL that routes to an action. This allows you to then hook into the action and perform tasks.
These routes can be used for capturing callbacks like a PayPal IPN.

Routed Actions

Creates a URL to route a request to an action.

Custom category and page extensions vs Routed Actions