I've always been annoyed by the way how Xdebug's stack traces looked liked. So I spend some time on making them look better. I will show the differences according to the following script:

<?php
    ini_set('xdebug.show_local_vars', 'on');
    ini_set('xdebug.dump_globals', 'on');
    ini_set('xdebug.dump.GET', '*');
    ini_set('xdebug.collect_params', 'on');
    ini_set('xdebug.var_display_max_depth', 2);
    function foo( $a )
    {
        for ($i = 1; $i < $a['foo']; $i++)
        {
        }
    }
    set_time_limit(1);
    $c = new stdClass;
    $c->bar = 100;
    $c->foo = "12";
    $a = array(
        42 => false,
        'foo' => 912125235,
        0 => null,
        3.141592654,
        "testing",
        array(),
        $c, new stdClass,
        fopen( '/etc/passwd', 'r' )
    );
    foo( $a, 42, null, false, "testing",
        $c, fopen( '/etc/passwd', 'r' ) );
?>

Old:

New:

The code for this will make it into CVS soonish.