I am developing an application using zend framework. In the application I have to provide a URL for each user like mydomain.com/[username] then public will be able to view
Try using Apache .htaccess mod_rewrite.
4) Rewriting yoursite.com/user.php?username=xyz to yoursite.com/xyz
Have you checked zorpia.com.If you type hxxp://zorpia.com/roshanbh233 in browser you can see my profile over there. If you want to do the same kind of redirection i.e
hxxp://yoursite.com/xyz to hxxp://yoursite.com/user.php?username=xyz then you can add the following code to the .htaccess file.
RewriteEngine On
RewriteRule ^([a-zA-Z0-9_-]+)$ user.php?username=$1
RewriteRule ^([a-zA-Z0-9_-]+)/$ user.php?username=$1
source: http://roshanbh.com.np/2008/03/url-rewriting-examples-htaccess.html