PHP 5.3.0 has significantly improved performance and parsing of INI files, and adds several new syntax features.
php.ini-development contains settings recommended
     for use in development environments. php.ini-production
     contains settings recommended for use in production environments.
    
   [PATH=/opt/httpd/www.example.com/] and 
     [HOST=www.example.com]. Directives set in these 
     sections cannot be overridden by user-defined INI files or at 
     runtime. More information about these sections can be found 
     here.
    
   E_ERROR error is emitted at startup.
    
   "ini-variables" can now be used almost anywhere in a
     php.ini file.
    
   The following new ini directives have been added:
user_ini.filename and
     user_ini.cache_ttl have been added to control the use
     of user INI files.
    
   mbstring.http_output_conv_mimetype. 
     This directive specifies the regex pattern of content types for which 
     mb_output_handler() is activated.
    
   The following ini directives have new default values:
"1" (enabled) by default.
    
   "10" to "100".