A report is out from the Wall Street Journal today, indicating that Amazon is working on a new line of hardware products, which includes a smartphone with 3D display capability, an additional smartphone, and an audio-only streaming device. These are in addition to the previously rumored set-top box. Collectively, the report (which cites people familiar with the company’s plans as the source) says, the projects are known as Project A, B, C and D or “The Alphabet Projects” and are in development in Amazon’s Lab126 facility.

The one smartphone would be able to display 3D images without users having to wear glasses, and would use retina-tracking technology to let people use their eyes to navigate through content, which would appear to float above the screen like a hologram, according to the report. The device would reportedly support 4G LTE and would come with Qualcomm chips.

Finally, the Journal’s sources suggested that Amazon’s efforts could lead to a streaming music service that would compete with the likes of Pandora and Spotify, and presumably accompany the aforementioned audio-streaming device. They also indicated that the company wants to release some of the offerings in the coming months, but they could be abandoned if financial or performance concerns become too great.

We’ve been hearing rumors about Amazon smartphones for quite some time. Speculation has been happening for years. Frankly, it would make a great deal of sense alongside its Kindle and Kindle Fire devices as the company increasingly competes with Apple and Google.

In March, rumors heated up that Amazon planned to launch a Kindle Phone in Q2.