DeleGate is a multi-purpose application level gateway or proxy server that mediates communication of various protocols, applying cache and conversion for mediated data, controlling access from clients, and routing toward servers. It translates protocols between clients and servers, converting between IPv4 and IPv6, applying SSL (TLS) to arbitrary protocols, merging several servers into a single server view with aliasing and filtering. It can be used as a simple origin server for some protocols (HTTP, FTP, and NNTP).
edtFTPj/PRO is a Java library that performs secure file transfers. It supports FTPS (FTP over SSL), both explicit and implicit modes, and SFTP (FTP via SSH). It also supports asynchronous transfers and FTP connection pools. All major FTP operations are supported, including both active and passive modes. It provides a progress monitor interface, allowing applications to receive progress updates for their file transfers. The library is built on the open source edtFTPj and shares its API. It is compatible with Android 1.5 and above.
ftp-ssl is similar to the standard FTP client and it interoperates with normal ftpd, but it uses SSL authentication and encryption. It checks if the other side is also talking SSL, and if not it falls back to the normal FTP protocol. Advantages over normal FTP include encryption of passwords and transmitted data, preventing network sniffers from acquiring secret information (most notably passwords).
KDX is a powerful cross-platform BBS-style encrypted Internet communications system that provides messaging, news, file and folder transfer, voice chat (Internet Telephone), text chat, remote access, trackers, and more. It uses strong encryption to protect communications for security and privacy. It is useful for groups that need to collaborate on a project via the Internet. It is also very useful for remote administration of a computer. It uses a client/server architecture.
JAFS is an FTP server with some unique features. It features easy management via an encrypted Web browser, external JRMP/IIOP consoles or SOAP, SFTP support, password encryption with SHA-256 or MD5, one-time password and miscellaneous IP blocking methods, firewall/NAT traversal via UPNP use, a DynDNS integrated client, customisation via upload/download filters and scripting capabilities, and network integration with NT users or RADIUS servers.