I’ve been using OpenELEC for a few years now, having it installed on an older Apple TV 1 (ATV1) and more recently on my Raspberry Pi 2 for use as a media centre. OpenELEC drastically simplified a kodi installation on any supported hardware & by aiming OpenELEC at being an appliance they managed to make a lightweight & rock solid kodi OS.
It would seem over the past 6 months or so, development of OpenELEC and support for OpenELEC has wound down. Maybe the developers have other projects to focus on, but I found that it wasn’t being updated as often as I would like. I then spotted LibreELEC which is operated by a small board of developers focused on creating a system with just enough OS for Kodi. This is excellent news for anyone running Kodi on a Raspberry Pi as the filesystem requirements are small & only enough processes & services run in order to support Kodi, meaning precious resources are freed up on slower hardware.