S3Fox Organizer!

Cyberduck is an open source FTP client.

The SME Enterprise File Share and Sync Solution provides a comprehensive control and management solution to enable secure cloud collaboration across data points for corporations.

Jungle Disk is a leading provider of online storage software and services, leveraging the Amazon S3 platform and Rackspac infrastructure to provide easy to use and cost effective online storage and backup to our customers. The multi-platform Jungle Disk software allows users to access an unlimited online storage space via a virtual drive and also includes comprehensive automatic backup features.

Gladinet Cloud Desktop mounts cloud storage to your local desktop PC. It is a simple desktop application.

CloudBerry Explorer makes managing files in Amazon S3 storage EASY. By providing a user interface to Amazon S3 accounts, files, and buckets, CloudBerry lets you manage your files on cloud just as you would on your own local computer. PRO version offers FTP support.

S3 Browser - Windows Client for Amazon S3. User Interface for Amazon S3. Allows you to manage your Amazon S3 Buckets and files with ease!

CrossFTP is a free FTP, Amazon S3, Amazon Glacier, and cloud storage client.* CrossFTPs main features: Multi-tab Navigation; Unicode support; Bonjour Service Discovery; Archive browsing(.zip,.tar.gz,etc.); Auto-reconnecting and anti-idle; and more.* CrossFTP Pro version is available by a license fee, which further features: Mutli-Thread transfer; Synchronization; WebDav, SFTP, FTPS, Advanced Amazon S3/Glacier support; CouldFront and URL sign support; Remote file edit; FXP; and much more.

Yarkon is a a modern, responsive and intuitive web based user interface for Amazon S3. Use it to manage buckets, create folders, upload and share files - anything that you normally do with S3, but with a fluent, intuitive and feature rich user experience, similar to what you have when using your PC. Drag & drop, context menus, copy-paste, it is all there.

DragonDisk is multithreaded S3 Client with lots of useful features and an intuitive graphical user interface.

Amazon S3 gui client Bucket Explorer to create and manage bucket, for web hosting and sharing S3 files. Use it as FTP tool for S3.

Cloud Turtle is a free cloud explorer that connects you to three different storage services: Amazon S3, Nirvanix and Timeline Cloud