We are planning to establish a mechanism that provides a central location for participants to exchange data files - and thus meet the particular need of establishing a procedure to submit data files into a community database. In the past we have done this by providing a group of users individual logins and passwords as well as group privileges to log-on to ftp to the central computer. This works well for those who are somewhat familiar with unix but introduces barriers for those unfamiliar with unix commands, shared spaces, and the concept of group file privileges.

Four alternatives to exchanging files include: 1) ftp, 2) subversion, 3) remote mount, and 4) WebDAV. The scope of the project pervasive availability would be: a) involves fairly small number of people (PAL 10; CCE 25); b) involves some remote geographic locations such as New York or Oregon; and c) includes desire to ensure some security through defined groups/accounts.

First thought is that subversion is not highly transparent for most users. We haven’t yet discussed the security arrangements for group use of ftp. We have, however, successfully used the remote mount option as a file exchange mechanism in some of our early iOcean supported collaborative work, ie with PAL and CCE projects. This approach makes use of three protocols with a fair amount of network overhead (afp for mac; smb for pc; nfs for unix).

Webdav is an approach JRW has been investigating through the Apple’s .mac endeavor with iDisk (remote mounts). WebDAV is the open source underlying environment that supports desktop disk mounts. In addition, it uses a single protocol (http) across all platforms and can likely be part of existing authentication schemes (she says hopefully). Webdav does not allow for versioning, but to me this seems a minor issue as I’m comfortable with engaging the user in naming their own files rather through an automated mechanism. This technology is being used by macworld’s .mac file sharing service which makes it a bit of a mystery as to why we haven’t heard about more groups locally or in our communities making use of it.

iDisk creates an icon on your desktop, allowing you to drag and drop files just as with any other type of hard drive. Xdrive and MySpace have similar features but both these technologies are available only to PC.

From a community point of view, the WebDAV (http://www.webdav.org) defines itself as “WebDAV stands for “Web-based Distributed Authoring and Versioning”. It is a set of extensions to the HTTP protocol which allows users to collaboratively edit and manage files on remote web servers.” Dav is more general than an API, it is a protocol, an extention of the http protocol. Subversion uses the WebDAV protocol and has a WebDAV interface.

Articles:
http://ftp.ics.uci.edu/pub/ietf/webdav/intro/webdav_intro.pdf
http://www.cs.ucsc.edu/~ejw/papers/kim_oss04.pdf