KCFinder is free open-source replacement of 
CKFinder web file manager.
It can be integrated into FCKeditor, CKEditor, and TinyMCE WYSIWYG web editors or your custom web applications to upload and manage images, flash movies, and other files that can be embedded in an editor's generated HTML content.
Features
Ajax engine with JSON responses
Multiple files upload
Upload files using HTML5 drag and drop from local file manager
Download multiple files or a folder as single ZIP file
Select multiple files with the Ctrl/Command key
Clipboard for copying, moving and downloading multiple files
Easy to integrate and configure in web applications
Option to select and return several files. For custom applications only
Resize uploaded images. Configurable maximum image resolution
PNG watermark support
Configurable thumbnail resolution
Automaticaly rotate and/or flip uploaded images depending on the orientation info EXIF tag if it exist
Multiple themes support
Multilanguage system
Preview images in full size... More Info »
Compatibility
KCFinder is officialy tested on Apache 2 web server only, but probably it will work on other web servers.
PHP 5.3 or better is required. Safe mode should be off.
At least one of these PHP extensions is required: GD, ImageMagick or GraphicsMagick.
To work with client-side HTTP cache, the PHP must be installed as Apache module.
KCFinder supports MIME type recognition for the uploaded files. If you plan to use this feature, you should to load Fileinfo PHP extension.
PHP ZIP extension should be loaded in order to have an option to download multiple files and directories as single ZIP file.
Automatic rotating and flipping images requires PHP EXIF extension.
