Top free applications to aid in web design and development

FileZilla FTP Client -
A FTP client to upload documents from your computer to your web server. Also supports SFTP for secure transfering of files.

xampp -
A bundled installer of Apache, PHP, MySQL and a few other programs. This allows you to set up a server on your computer accessible through http://localhost which saves you having to upload the files to a server during development.

Notepad++ -
An extension of notepad in Windows with more features including syntax highlight for PHP, HTML, javascript and many more languages.

GIMP (GNU Image Maninpulation Program) -
A worthy alternative to the hugely expensive Photoshop. -
Based on the simplicity of MS Paint, takes this a lot further with the introduction of many tools that are present in GIMP and Photoshop.