1. 
      Migrating from PHP 4 to PHP 5
     
 
      Although PHP 5 offers many new features, it's designed to be as
      compatible with earlier versions of PHP as possible with little
      functionality being broken in the process.
     
      Be sure to read the appropriate PHP 5
      migration appendix of this manual as it contains even more
      information on the topic of migrating to PHP 5.
     
2. 
      Does MySQL work in PHP 5?  It seemed to have disappeared.
     
 
      MySQL is supported with the only
      change being that MySQL support is no longer enabled by 
      default in PHP 5.  This essentially means that
      PHP doesn't include the --with-mysql
      option in the configure line so 
      that you must now manually do this when compiling PHP. Windows users will 
      edit php.ini and enable the php_mysql.dll DLL as
      in PHP 4 no such DLL existed, it was simply built into your Windows
      PHP binaries.
     
      Also, the MySQL client libraries are no longer bundled with PHP.  More
      details on this topic are covered in 
      the following FAQ and
      be sure to read the MySQL section
      for details on installing MySQL.  An example configure line would be 
      --with-mysql=/usr while Windows users
      will need the libmySQL.dll available to the system.
     
3. 
      I hear PHP 5 has an entirely new OOP model, will my existing OOP code
      work?  Where do I find information on these new OOP features? 
     
4. 
      So besides the new OOP model, what else has changed in PHP 5?  Also, is
      there a PHP 5 specific version of the PHP manual?
     
 
      Few other changes exist, see the migration
      5 appendix for details.  There won't be a PHP 5 specific
      version of the manual as the bulk of PHP remains the same.