GridFTP is a file transfer protocol, which provides extensions for security and transfer models on top of FTP protocol. The security infrastructure uses x509 certificates as credentials both in the client and in the service end of the transfer. It is possible to perform third party transfers as well as use multiple TCP connections per transfer to achieve high performance. CoGkit provides open source Java libraries for GridFTP.
WebDAV is a set of protocol extensions on top of HTTP protocol. DAV stands for Distributed Authoring and Versioning and the protocol allows users to collaboratively edit and manage files on a remote server. WebDAV server can be mounted to Linux systems as a remote volume and in Windows systems it can be seen as a remote network volume. Jakarta Slide provides open source Java libraries for WebDAV. The protocol runs on top of HTTP and it is easy to use when only single port needs to be opened for the traffic.