S3cmd : Command Line S3 Client and Backup for Linux and Mac
Amazon S3 is a reasonably priced data storage service. Ideal for off-site file backups, file archiving, web hosting and other data storage needs. It is generally more reliable than your regular web hosting for storing your files and images. Check out about Amazon S3 to find out more.
S3cmd is a free command line tool and client for uploading, retrieving and managing data in Amazon S3 and other cloud storage service providers that use the S3 protocol, such as Google Cloud Storage or DreamHost DreamObjects. It is best suited for power users who are familiar with command line programs. It is also ideal for batch scripts and automated backup to S3, triggered from cron, etc.
S3cmd is written in Python. It's an open source project available under GNU Public License v2 (GPLv2) and is free for both commercial and private use. You will only have to pay Amazon for using their storage.
Lots of features and options have been added to S3cmd, since its very first release in 2008.... we recently counted more than 60 command line options, including multipart uploads, encryption, incremental backup, s3 sync, ACL and Metadata management, S3 bucket size, bucket policies, and more!
S3Express : Command Line S3 Client and S3 Backup for Windows
S3Express is a commercial S3 command line tool for Windows. Differently from S3cmd, S3Express is designed to run specifically on Windows, it is self-contained in one executable (s3express.exe) and does not require any additional libraries or software to be installed to run. It's very compact and has very small footprint: the entire program is less than 5MB. It's very easy to install on Windows servers, clients, desktops and laptop computers alike.
With S3Express you can list and query S3 objects using conditional filters, manage S3 objects' metadata and ACLs, upload files to S3 using multipart uploads and multiple concurrent threads, upload only new or changed files to S3 for automated backup (= incremental backup), delete multiple S3 objects, copy S3 objects, etc. using the Windows command line.
All operations in S3Express are multithreaded (fast), automatically retryable (network-failure resistant), and interruptible (= all commands can be stopped and restarted at any time). Connections to Amazon S3 are made using secure http (https), which is an encrypted version of the HTTP protocol, to protect your files while they're in transit to and from Amazon S3 storage servers.