You can clone with
HTTPS or Subversion.
Feeds without dates seem to always land on the bottom of the moon. (They also appear to be posted out of order).
For example http://feeds.feedburner.com/QubdupAtFreesound?format=xml ( valid http://feed1.w3.org/check.cgi?url=http%3A//feeds.feedburner.com/QubdupAtFreesound%3Fformat%3Dxml - apparently pubDate is optional? )
I know that moonmoon uses no database, so I don't know whether it is possible to track dates 'manually' .
Each time an item with a new guid appears, the could be used to approximate the pubDate of the item.
I plan to add an optional database (sqlite) to moonmoon so we can keep more history, fetch date, sort stuff, etc.
Cache files and/or plaintext databases are not a viable solution? I believe many of the very cheap hosts don't support sqlite.
Sqlite would be optional. Hosts that do not support sqlite simply fallback to normal file based cache.
For clarification: date-less, valid feeds are not supported right now and will require sqlite in the future?