There are many different OpenELEC builds and the most appropriate one for your system will depend on what hardware you're running. These are the builds available at this time:
OpenELEC will no longer support this builds. Since OpenELEC 4.0 (gotham) all of them had been governed into one, the Generic builds. If you are using one of these builds, you will need to migrate to the Generic builds. If you need to migrate from an older unsupported build, please follow these instructions:
ION / ION2
ION and ION2 HTPCs typically have an Intel Atom or Core i3 CPU and an nVidia ION GPU. ION has been a popular platform for pre-built HTPC systems in recent years and is currently the most-stable and most widely used OpenELEC image. If you have older Intel Atom CPUs that support only 32-bit software use the i386 image. Otherwise use the x86_64 image.
Fusion HTPCs use AMD APU processors with integrated AMD Fusion graphics. Fusion is becoming a popular platform for home-built and pre-built HTPC systems. Initial teething troubles with XVBA accelerated graphics support in XBMC have been addressed and these are now considered stable.
This is NOT a generic image for anything with an Intel CPU, it is tailored for HTPC systems that use Intel GMA integrated graphics including the latest Intel "Sandy Bridge" hardware.
This image has been developed in partnership with Xtreamer and has been tailored to support the Xtreamer Ultra hardware only.
The mk1 (silver) AppleTV makes an excellent and cheap XBMC box, especially if upgraded with a Broadcom BCM970012 or BCM970015 CrystalHD card. This image is tailored to the very-specific hardware found in the Apple TV. OpenELEC uses the nouveau graphics driver to support audio over the HDMI connection. Installing OpenELEC onto an Apple TV requires a different installation procedure to other HTPC platforms.
The Generic image is a "catch-all" build containing more drivers than any other image. If you have a home-built HTPC that is not based on ION, ION2, Intel or Fusion GPU chipsets, or you are going to install OpenELEC onto a laptop or desktop computer with a Nvidia videocard, this is probably the best image to use. The Generic images may require a moderate level of post-installation tweaking to get items like sound configuration correct.