To avoid further confusion: The krb5 PHP extension is now hosted on
PECL. There now is a public SVN repository under
http://svn.php.net/repository/pecl/krb5/trunk/ which contains some bug fixes and improvements over the here published rc2 version. Please use the SVN version.
Also feel free to use the PECL bug tracker if you experience any issues.
UPDATE: The library location issues that many people suffered from should now be fixed. Sorry it took so long.