When Google began work on Project Ara in 2013, the idea seemed like the kind that people would get excited about for a while, but would never make it to market, at least not in the form Google promised. The idea was that Ara would be an entirely customizable phone. You'd be able to replace any independent component, from the camera and screen to the RAM and processor. The purpose, of course, would be to allow for incredibly niche-style phones without the need to manufacture a small number, making the devices less expensive.
Unfortunately, Google has never been able to deliver on any of their promises with Ara. A prototype of the platform, "Spiral 2," was shown off in January of last year, with planned market testing in Puerto Rico later in the year. That market test never materialized, because it turned out that the device was a lot harder to build than they expected. Between issues with component communication and, more importantly, issues keeping the components magnetically connected, the release was delayed, with no new date.
At Google I/O 2016, the company showed off another prototype, dubbed "Developer Edition." This version was not quite the same, with the screen, processor, memory and more built-in to the base plate and no longer replaceable. It was promised that, later in the year, the prototype would be released to developers to begin the process of building modules for the platform, as well as building software specifically for Ara devices and modules. Unfortunately, this promise will go the same way as the last - never coming to pass.
Google has shelved Project Ara, effective immediately. The Developer Edition will not be released, and the consumer market will not see a version in 2017. The concept, however, lives on. In part, the concept still exists in the Moto Z family, the LG G5 and the HP Elite x3. All 3 of these devices offer a proprietary extensibility system, which allows additional components to be added - but only one at a time. For example, the consumer-focused Moto Z offers a Hasselblad camera, and the HP Elite x3 offers a dedicated barcode reader.
While it is a shame that the Ara project never came to fruition, there is some good news. Google is open to the idea of another company picking up the torch and licensing the Ara technology for a future release. Phone manufacturer Yezz had an existing relationship with the project, and is known for dabbling in untested technologies, which could lead to them releasing a phone in this category eventually, but that is pure speculation. For the time being, though, we will have to settle for one component at a time.