1.5. Keeping Up with PHP and MySQL Changes

PHP and MySQL are open source software. If you've used only software from major software publishers — such as Microsoft, Corel, or Adobe — you'll find that open source software is an entirely different species. It's developed by a group of programmers who write the code in their spare time, for fun and for free. There's no corporate office.

Open source software changes frequently, rather than once every year or two like commercial software does. It changes when the developers feel that it's ready. It also changes quickly in response to problems. When a serious problem is found — such as a security hole — a new version that fixes the problem can be released in days. You don't receive glossy brochures or see splashy magazine ads for a year before a new version is released. Thus, if you don't make the effort to stay informed, you might miss the release of a new version or be unaware of a serious problem with your current version.

Visit the PHP and MySQL Web sites often. You need to know the information that's published there. Even if you don't subscribe to any other mailing lists, subscribe to the announcement mailing list, which delivers e-mail only occasionally, with information you need to know. So, right now, before you forget, hop over to the PHP and MySQL Web sites and sign up for a list or two at www.php.net/mailing-lists.php and http://lists.mysql.com.

In addition, if you're developing on your local computer and uploading to your Web site, you need to have the same versions of PHP and MySQL installed locally that are installed on your Web host. You need to be sure that the scripts you develop locally run the same way and produce the same output when uploaded to your public Web site.