I recently finished (I hope) a new major-mode for writing NetRexx. It's 60kb
large. Would it be frowned upon if I were to post this in gnu.emacs.sources?
I don't think you'll be blamed for it.
It's really not that large. But note that many newsservers simply ignore
large messages, so I recommend you post a URL instead.
Other people disagree and think the full source is better because it then
gets archived as part of gnu.emacs.source archive, so if you post a URL,
make sure that the location will "live for ever".
In any case, a good thing to do is to also put the package in emacswiki.org.
Stefan