Can someone tell me the difference between PHP4 & PHP5?

Public Comments

1. try www.php.net
2. From php.net's PHP5 change log: Version 5.0.0 Beta 1 29-Jun-2003 * Switch to using Zend Engine 2, which includes numerous engine level improvements. A full list is available at http://www.php.net/zend-engine-2.php. * The SQLite (http://www.hwaci.com/sw/sqlite/) extension is now bundled and enabled by default. (Wez, Marcus, Tal) * Improved the speed of internal functions that use callbacks by 40% due to a new internal fast_call_user_function() function. (Sterling) * Completely Overhauled XML support (Rob, Sterling, Chregu, Marcus) o Brand new Simplexml extension o New DOM extension o New XSL extension o Moved the old DOM-XML and XSLT extensions to PECL o ext/xml can now use both libxml2 and expat to parse XML o Removed bundled expat * Removed the bundled MySQL client library. (Sterling) * New php.ini options: o "session.hash_function" and "session.hash_bits_per_character". (Sascha) o "mail.force_extra_paramaters". (Derick) o "register_long_arrays". (Zeev) * Improved the streams support: (Wez, Sara, Ilia) o Improved performance of readfile(), fpassthru() and some internal streams operations under Win32. o stream_socket_client() - similar to fsockopen(), but more powerful. o stream_socket_server() - Creates a server socket. o stream_socket_accept() - Accept a client connection. o stream_socket_get_name() - Get local or remote name of socket. o stream_copy_to_stream() o stream_get_line() - Reads either the specified number of bytes or until the ending string is found. o Added context property to userspace streams object. o Added generic crypto interface for streams (supports dynamic loading of OpenSSL) o Added lightweight streaming input abstraction to the Zend Engine scanners to provide uniform support for include()'ing data from PHP streams across all platforms. o Added 'string.base64' stream filter. o Renamed stream_register_wrapper() to stream_wrapper_register(). o Added "ftp://" wrapper support to opendir(), stat() and unlink(). o Added context options 'method', 'header' and 'content' for "http://" fopen wrapper. * Improved the GD extension: (Pierre-Alain Joye, Ilia) o imagefilter() - Apply different filters to image. (Only available with bundled GD library) o Antialiased drawing support: + imageantialias() - (de)active antialias + imageline() and imagepolygon() antialias support * Changed the length parameter in fgetss() to be optional. (Moriyoshi) * Changed ini parser to allow for handling of quoted multi-line values. (Ilia) * Changed get_extension_funcs() to return list of the built-in Zend Engine functions if "zend" is specified as the module name. (Ilia) * Changed array_search() to accept also objects as a needle. (Moriyoshi) * Changed ext/mcrypt to require libmcrypt version 2.5.6 or greater. (Derick) * Changed uniqid() parameters to be optional and allow any prefix length. (Marcus) * Added new iconv functions. (Moriyoshi) o iconv_strlen() o iconv_substr() o iconv_strpos() o iconv_strrpos() o iconv_mime_decode() o iconv_mime_encode() * Added misc. new functions: o ldap_sasl_bind(). (peter_c60@hotmail.com, Jani) o imap_getacl(). (Dan, Holger Burbach) o file_put_contents(). (Sterling) o proc_nice() - Changes priority of the current process. (Ilia) o pcntl_getpriority() and pcntl_setpriority(). (Ilia) o idate(), date_sunrise() and date_sunset(). (Moshe Doron) o strpbrk() - Searches a string for a list of characters. (Ilia) o get_headers() - Returns headers sent by the server of the specified URL. (Ilia) o str_split() - Breaks down a string into an array of elements based on length. (Ilia) o array_walk_recursive(). (Ilia) o array_combine(). (Andrey) * Added optional parameter to get_browser() to make it return an array. (Jay) * Added optional parameter to openssl_sign() to specify the hashing algorithm.(scott@planetscott.ca, Derick) * Added optional parameter to sha1(), sha1_file(), md5() and md5_file() which makes them return the digest as binary data. (Michael Bretterklieber, Derick) * Added optional parameter to mkdir() to make directory creation recursive. (Ilia) * Added optional parameter to file() which makes the result array not contain the line endings and to skip empty lines. (Ilia) * Added new range() functionality: o Support for float modifier. (Ilia) o Detection of numeric values inside strings passed as high & low. (Ilia) o Proper handle the situations where high == low. (Ilia) o Added an optional step parameter. (Jon) * Added encoding detection feature for expat XML parser. (Adam Dickmeiss, Moriyoshi) * Added missing multibyte (unicode) support and numeric entity support to html_entity_decode(). (Moriyoshi) * Added IPv6 support to ext/sockets. (Sara) * Added input filter support. See README.input_filter for more info. (Rasmus) * Added a replace count for str_[i]replace(), see #8218. (Sara) * Fixed is_executable() to be available also on Windows. (Shane) * Fixed dirname() and strip_tags() to be binary-safe. (Moriyoshi) * Fixed bug #24098 (crash in pathinfo()). (Ilia) * Fixed bug #21985 and #22064 (various mb_send_mail() issues). (Moriyoshi) * Fixed bug #21600 (Assign by reference function call changes variable contents). (Zeev) The full list of changes for PHP5 are here: http://www.php.net/ChangeLog-5.php
3. There really isnt a diffrence, same old thing since day one, i think its just a couple more functions added.