Use an indent of 4 spaces, with no tabs. This helps to avoid problems with diffs, patches, SVN history and annotations.
For Emacs you should set indent-tabs-mode to nil. Here is an example mode hook that will set up Emacs (ensure that it is called when you are editing PHP files):
(defun pear/php-mode-init() "Set some buffer-local variables." (setq case-fold-search t) (c-set-offset 'arglist-intro '+) (c-set-offset 'arglist-close '0) ) (add-hook 'php-mode-hook 'pear/php-mode-init)
Here are Vim rules for the same thing:
set expandtab set shiftwidth=4 set softtabstop=4 set tabstop=4
It is recommended to keep lines at approximately 75-85 characters long for better code readability. Paul M. Jones has some thoughts about that limit.