Spellchecking
Some users have requested some form of spell checking, hinting etc.
This looks like the library for the job:
http://hunspell.sourceforge.net/
Yeah, this should be a handy feature.
10-4
Is the plugin api powerful enough to implement this?
Honestly I can't say. I never read the API code nor developed a plugin unfortunately. Would be great to have a contributor who could cover that part.
We have implemented an /editor command (#1485) - vim can be used with :set spell spelllang=en for spell checking.
Launching an editor for every message sounds a bit tedious.
WeeChat is able to use aspell and it works really good with multiple languages enabled at the same time.