Tranche is file storage and dissemination software. Designed and built with scientists and researchers in mind, Tranche can handle very large data sets, is secure and scalable, and all data sets are citable in scientific journals. Features include a fully decentralized architecture, support for very large files, very long-term file persistence/preservation, file immutability/integrity, provenance, encryption, licensing, versioning, and citability.
Libdroplet is a C library that implements the S3 protocol and facilitates the writing of tools that interact with S3 services. Libdroplet comes with a set of features which enhances the S3 protocol, including a multi-profile system, full multi-threading, virtual directories with true absolute and relative path support, on-the-fly encryption/decryption and buffered I/O, management of storage pricing, and simplified metadata management.
QT Cloud Drive is a cross-platform desktop application for connecting to Amazon Cloud Drive. It can be more convenient than using Web-based access because it allows you to remain constantly signed in and allows you to drag and drop files between the cloud drive and other desktop applications.
Seafile is a file synchronization and collaboration platform. It comes with Dropbox-like file syncing, but is designed to be better suited to teamwork. You can build a file syncing and collaboration service for your team on your servers. It can also be used to build your own Dropbox for personal use.
Megatools is a collection of programs for accessing the Mega service from the commandline of your desktop or server. It allows you to copy individual files as well as entire directory trees to and from the cloud. You can also perform streaming downloads (for example, to preview videos and audio files) without needing to download the entire file. The tools are robust and optimized for fast operation, as fast as the Mega servers allow. Memory requirements and CPU utilization are kept at minimum. You can register an account using a "megareg" tool, with the benefit of having true control of your encryption keys.