As of mojoPortal CMS 126.96.36.199 or newer, using IIS 7 and Integrated Pipeline mode, it is now possible to use extensionless URLs out of the box. This only works when using Integrated Pipeline mode; it will not work if you have configured a "Classic" application pool for the site.
Next, you need to find this in the appSettings section:
<add key="AllowChangingFriendlyUrlPattern" value="false" />
You should copy this setting and put it in your user.config file and change the value to "true".
Then, after touching web.config, you will see a new dropdown in Administration > Site Settings:
There are two options: page-name.aspx and page-name, which is for extensionless URLs.
It's also possible to use extensionless URLs on Mono with Apache 2, if the site is configured for Mono to handle all requests.
In some cases you "may" also need to change this in Web.config to get it working correctly:
and change it like this:
What About IIS 6?
Things are not so pretty in making extensionless URLs work under IIS 6. It can be done by setting up wildcard mapping, and there are ways of doing it with third party ISAPI filters.
There is also a feature in .NET 4 that can be used as discussed here, and another approach is documented here.
Updated 2011-08-22 by Joe Audette
Updated 2012-02-09 by Jamie Eubanks