Indenting and Line Length

Use an indent of 4 spaces, with no tabs. If you use Emacs to edit PEAR code, you should set indent-tabs-mode to nil. Here is an example mode hook that will set up Emacs according to these guidelines (you will need to ensure that it is called when you are editing PHP files):

(defun php-mode-hook ()
  (setq tab-width 4
        c-basic-offset 4
        c-hanging-comment-ender-p nil
        indent-tabs-mode
  (not
    (and (string-match "/\\(PEAR\\|pear\\)/" (buffer-file-name))
      (string-match "\.php$" (buffer-file-name))))))

Here are vim rules for the same thing:

set expandtab
set shiftwidth=4
set softtabstop=4
set tabstop=4

It is recommended that you break lines at approximately 75-85 characters. There is no standard rule for the best way to break a line, use your judgment and, when in doubt, ask on the PEAR Quality Assurance mailing list.