I've decided to drop support for Atom 0.1 formats - if they even exist. I can't seem to find any documentation or even mention that they really exist.
I've also been teetering back and forth with regards to support creation of outdated formats. Specs say that Atom 0.3 is depreciated and should not be used. I could take this as meaning my classes should not be allowed to create Atom 0.3 and 0.2 feeds.
But then again, why not? I think any respectable person would simply not create 0.3 feeds, and automatically use 1.0. But what about unique situations? Maybe somebody wants to write a program which can convert a modern feed to a sub-modern feed... for some reason. Who am I to say they can't do that?
So, I'm almost certain I'm going to stick with "yes" - REALSyndication will support creation of any supported feed format.
I think a fun feature of this package is conversion. One could, with nearly no work, take a Atom 0.3 feed and output a 1.0 feed. Or even better, convert an RSS 1.0 to a 2.0.
To be honest though, I don't think anybody really wants these classes for output. Everybody wants input. But really, both could be useful. You could write your own feed aggregator that takes the newest articles from 20 dozen feeds of various formats, and creates a single Atom 1.0 feed that gets uploaded to your FTP server and becomes available for use elsewhere, such as on a PSP. Leave it running all the time on any computer, and viola!
Just an example from the top of my head. More than likely, the PSP supports multiple feeds instead of just one - I don't know, I don't care for the PSP. But the point is the same.