I have seen many open-source web applications such as Drupal and Wordpress with missing closing php tag (?>) in header and other include files. The application does work flawlessly, and I am curious to know why those closing tags are missing. According to the php.net manual, ...
The closing tag of a PHP block at the end of a file is optional, and in some cases omitting it is helpful when using include() or require(), so unwanted whitespace will not occur at the end of files and you will still be able to add headers to the response later. It is also handy if you use output buffering, and would not like to see added unwanted whitespace at the end of the parts generated by the included files.
Also, it should be noted that the closing tag of a block of PHP code automatically implies a semicolon; you do not need to have a semicolon terminating the last line of a PHP block.
