Plex

Plex can be used with Kodi, but it takes a bit of fiddling. This is what I had to do in Ubuntu 15.10 (March 2016).

PleXBMC is more or less abandoned; another project PlexKodiConnect is under active development now, based on the Emby add-on. Download it and its dependency zips and install (System → Add-ons → Install from Zip) in a fresh Kodi instance in this order:

• https://github.com/beenje/script.module.requests/releases
• https://github.com/croneter/plugin.video.plexkodiconnect.movies/releases
• https://github.com/croneter/plugin.video.plexkodiconnect.tvshows/releases
• https://github.com/croneter/PlexKodiConnect/releases

Make sure home users on Plex are disabled otherwise it (currently) doesn't authenticate properly.

Note for Ubuntu pre 16.04

Playback from Plex won't work unless you have python-cryptography version 1.1 or better installed. Ubuntu 15.10 ships with 1.0 which contains threading bugs that mean it doesn't work in Kodi 16, since it runs its scripts in Python 2.7 which sucks at Unicode and threading. Python 3 was only released eight years ago so it's far too soon to upgrade to that.

sudo apt-get remove python-cryptography
sudo apt-get install python-pip python-dev libssl-dev libffi6 libffi-dev
sudo pip install cryptography