Gerade eben via digg.com gefunden und eigentlich für jeden PHP Entwickler interessant…
As a php web developer, you should know that php is probably the language that has the biggest code repository. So no matter what module you want to include in your project there should be an open source solution.
This can help in various ways, but just in case you can’t think of one, here I put a few :
- Open source is worked by many people, so the result is for sure better than one man’s work
- You can have free updates to your code, while otherwise you should code the updates each time something new comes up
- You save development time while your project is getting better
Anyway, after many years as a web developer, I’ve compiled a list of php classes that can be easily integrated in any project and I am regularly use.
Sending Emails
Sending emails is something very common for every web site. Php’s mail() 
function is good for this, but what if you want to attach a file, or send through an SMTP server, etc? Well in that case you should use phpmailer
User Manipulation
Another common module is the user module. With that you can manipulate users (login, logout, register, etc.) Personally I’ve never found a project that is good enough, so I created my own 
Php user class is a module that can be used even in established projects, as it uses variable data for database tables, fields, session variables, etc.
Fetching RSS Feeds
Ever wanted to fetch an rss feed from your project? Well there is always an easy way to fetch a feed but in most cases you need more than that. When that is the case you should definitely use Magpie RSS
Geotargeting
There are many times that you need to know where are your visitors coming from. Maxmind gives a solution to this. For a complete tutorial check this article
Grabbing Remote Content
Some times RSS is not enough so you need to grab the content of a web page and parse it. If you are a huge fun of preg you should not continue reading, but if you are not you definitely need the htmlSQL class The htmlSQL class allow you to access html values with SQL code. Nice huh?
Trackback
Sending and receiving trackbacks is vital for a web site in our age. And in fact it is very easy if you are using a class like php trackback
Template System
Another thing that all sites use is a template. A template engine can save you lots of time, while it can make display changes very easy. A complete template engine that most projects use is Smarty
BBcode
BBcode used to be a functionality for forums, but as more and more sites use it in order to be more friendly to their users, you might want to use BBcode to your site. The problem is that BBcode requires a lot of coding and I am not sure if you have the time for this. If you don’t you’ll find StringParser_BBcode class very useful
Paypal Payment Integration
As you may know paypal has a nice API for developers who want to integrate paypal payments in their sites. The paypal IPN integration class helps you make use of it and start accepting payments in 20 minutes.
Editor Controls
I don’t have a problem to make changes to a site using phpMyAdmin or a simple text area, but when it comes to my clients I have to give them more than that. A javascript WYSIWYG editor is a perfect solution but as it requires countless hours to get it done I would suggest you to use the tinyMCE control
Quelle: http://www.webdigity.com/index.php/topic,7333.0.10+projects+every+php+developer+should+use.html
