Aggregator must be ATOM enabled

here's a php script that converts ATOM to RSS:

http://www.composizioni.net/atom2rss/

Blogger only outputs Atom feeds by default. I don't know of any other tool that *only* outputs Atom. Feedburner is another tool that allows for conversion. We've got instructions on our support site:
http://support.bryght.com/adminguide/configure-rss-aggregator

In any case, this requires re-vamping syndication format input/output completely, which is on the "to do" list for 4.6.

Actually, I think it would be fairly easy to hack the script linked above into aggregator, but the author of the script makes no indication if it is GPL. (It's based on another person's script, so the odds are likely).

Not sure what "status: postponed" means but here are my 2c.

This is indeed an important feature, esp for those who use Drupal mainly as aggregator. On my site, the Drupal aggregator is monitoring over 500 blogs and a significant portion of those sites offer Atom feeds. Working with an external service as Feedburner makes managing/adding feeds more time consuming and cumbersome.

I agree. Atom support in the aggregator (and in core, i.e. providing an atom feed) is essential.

Status set to "active". We need to revisit this, and hopefully include for 4.7.

See also: Does Drupal Aggregator support Atom? (possible bounty)

Any thoughts on MagpieRSS? It is a PHP, expat-using, GPL-ed RSS and ATOM parser.

http://magpierss.sourceforge.net/

Here is a direct link to a CVS view of their rss_parse.inc page:
http://cvs.sourceforge.net/viewcvs.py/magpierss/magpierss/rss_parse.inc?...

I've done some related work (not with the intention of altering or contributing to aggregator.module, for a different project that involves feeds) a lightweight Drupal module wrapper for Magpie (all it does is expose a parsing function and generate a configuration page for Magpie's caching settings):

http://karchner.com/svn/code/drupal/modules/magpie/trunk/

I wonder if it would be much work to adapt aggregator.module to use that (or just include and use MagpieRSS direclty)

Set to duplicate. See 13941.

Also, regarding Magpie: I have long been an advocate of this, but especially after the recent XML-RPC issue, getting third-party code included in core would likely be very difficult.