Apache has mod_speling for automatic URL spell-correction. For example when on this site you can request the page using following format:
This module help visitor to get correct content instead of error 404 – document not found and you can also omit file extension such as .pl, .php, .html etc in urls references. It attempts to correct misspellings of URLs that users might have entered, by ignoring capitalization and by allowing up to one misspelling. This must be configured on massive web hosting server by ISP and web hosting service providers so the hosting customer can take advantage of this module.
Following steps demonstrates how to activate this module under Debian GNU/Linux:
A) Open your Apache modules configuration file:
# vi /etc/apache-perl/modules.conf
B) Append following line to this file:
LoadModule speling_module /usr/lib/apache/1.3/mod_speling.so
C) Save the file.
D) This module need to be configured via httpd.conf via CheckSpelling directive. You can configure it for entire site, particular virtual host or even via .htaccess file. Open your /etc/apache-perl/httpd.conf and add followint line in server config context:
E) Restart the apache:
# /etc/init.d/apache-perl restart
Please note that above steps are same under FreeBSD/Solaris for Apache web server except for file location i.e. httpd.conf and modules.conf. Please refer man page for more info.