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[ANN] Metalink (XML for describing downloads: mirrors, checksums, etc)

• From: "Anthony Bryan" <anthonybryan@g...>
• To: xml-dev@l...
• Date: Tue, 5 Feb 2008 15:16:28 -0500

Metalink is a cross-platform and cross-application open
standard/framework/file format for programs that download, including
download managers, BitTorrent clients, Web browsers, FTP clients, and
P2P programs. 30+ apps support it, including KGet in KDE 4.0 and
DownThemAll 1.0 beta (Firefox extension). Metalink is frequently used
for large file downloads like ISOs, for adding multiple files to a
download queue, or for automatic file verification or repair of errors
during downloads.

For increased convenience, it stores the multiple download locations
for a file (FTP/HTTP/P2P) in a single metafile with the extension
.metalink. This provides reliability in case one method fails. For
fast Internet connections, it also speeds up the process by allowing
chunks/segments of each file to be downloaded from multiple resources
at the same time (segmented downloading). Metalink supports listing
multiple partial and full file hashes/checksums along with PGP
signatures.

Here's a screenshot of a Ubuntu ISO metalink about to be downloaded
with DownThemAll: http://www.metalinker.org/images/dta_ubuntu.png

An example .metalink file:

<?xml version="1.0" encoding="UTF-8" ?>
 <metalink version="3.0" xmlns="http://metalinker.org">
   <files>
     <file name="example.ext">
     <verification>
       <hash type="md5">example-md5-hash</hash>
       <hash type="sha1">example-sha1-hash</hash>
     </verification>
     <resources>
       <url type="ftp" location="us"
preference="90">ftp://ftp.example.com/example.ext</url>
       <url type="ftp" location="uk"
preference="90">ftp://ftp.example.net/example.ext</url>
       <url type="http" location="us"
preference="90">http://example.com/example.ext</url>
       <url type="http" location="de"
preference="90">http://example.net/example.ext</url>
       <url type="bittorrent"
preference="100">http://example.org/example.ext.torrent</url>
     </resources>
     </file>
   </files>
 </metalink>

Those interested, please check out the site at
http://www.metalinker.org/ and our discussion mailing list at
http://groups.google.com/group/metalink-discussion

thanks,
-- 
(( Anthony Bryan ... Metalink [ http://www.metalinker.org ]
  )) Easier, More Reliable, Self Healing Downloads