Vim as a PHP IDE

See
(domain not renewed as of 2010 Nov. 4 - phpslacker.com/2009/02/05/vim-tips-for-php-programmers/ )

Once it's set up right, you can use :make % to check your PHP syntax before loading the code in a browser.

See also: http://2bits.com/articles/using-vim-and-xdebug-dbgp-for-debugging-drupal-or-any-php-application.html

As for simple PHP syntax highlighting for Drupal files in vim or gvim, here is my current ~/.vimrc file:

set nocompatible
set expandtab
set tabstop=2 shiftwidth=2 softtabstop=2
set autoindent
set foldmethod=indent

if has("autocmd")
  augroup phpfiles
    autocmd BufRead,BufNewFile *.php,*.module,*.theme,*.inc,*.install,*.info,*.engine,*.profile,*.test set filetype=php
  augroup END
endif

syntax on