Select the Right Editor for Your Code

Notepad++

http://notepad-plus-plus.org/ 
This is an open source software, a very nice replacement for Windows Notepad. Simply click on the Download to get the download link, at the time of this writing, the current version is 5.8.6. You can read for more information about this software at the homepage.

Run the downloaded file, as usual, Next, Next, … and the Notepad++:

It is very nice and light editor, with the code folding feature that can “fold” all the portion to make your code look nicer.

PDT (PHP Development Tools)

http://www.eclipse.org/pdt/ 
Go straight to the download page, http://www.eclipse.org/pdt/downloads/ and choose the All In Ones package (at the time of this writing, its version 2.2.0), download takes few minutes to complete, file size around 141MB.

The downloaded file is a zip file, unzip all to some place, maybe your desktop and you can directly use the PDT. There is no installation required, simply run the eclipse.exe file under eclipse folder. Then you will need to configure the workspace folder, there you can start your PHP coding. Anyway, it is advised that you copy the eclipse folder into your “C:\Program Files” folder, or if you are using Windows 64 bit, “C:\Program Files (x64)” folder.

PDT, built on top of the open source Eclipse platform, quite a powerful, and “heavier” PHP editor compare to Notepad++. You can build a PHP project here, manage your files in your project better, and it do comes with a bunch of feature to help your coding, which I am still exploring.