As far as I know XPI-addons appear in page "
about:addons" like in FF, although there's no way to it via menu yet. Just type it.
In general xpi-fils get located in K-M/browser/extensions/{gibberish}.xpi
Out-of-box the native included one is NewsFox.
Some come with more files in other folders too. If unclear, download the addon into a folder again and unzip it for examination, helps often though not always.
PS: no need to post duplicates, nothing can be overlooked here:
http://kmeleonbrowser.org/forum/addon.php?0,module=recent_messages
Edited 1 time(s). Last edit at 02/02/2016 05:47AM by siria.