Google is all set to unveil a variety of devices at its upcoming Oct. 4 event, including the new Pixel and Pixel XL smartphones and the Google Wifi router. However, the biggest thing at the event could possibly not be hardware, but software.

There have long been rumors of Google looking to merge Android for mobile devices with Chrome OS for laptops into a single operating system. The closest that Google has come to anything resembling the rumor is the ongoing work to allow Chromebooks, laptops which run on Chrome OS, to access the Google Play Store and run Android apps.

The rumor mill on the Android-Chrome OS merger is now once again buzzing due to a cryptic tweet by Android, Chrome OS and Google Play Store senior VP Hiroshi Lockheimer.

We announced the 1st version of Android 8 years ago today. I have a feeling 8 years from now we'll be talking about Oct 4, 2016.

— Hiroshi Lockheimer (@lockheimer) September 24, 2016

After the tweet, Android Police released a story on Andromeda, the internal codename for the merged Android-Chrome OS that claims it may be finally unveiled on Oct. 4. Android Police firmly believes that an announcement on Andromeda will be made at the upcoming Google event, as the unveiling of the merged operating system will be as significant as the launch of Android eight years ago.

Another report by 9to5Google claims that the company is now testing the hybrid operating system on the HTC-made Nexus 9, with evidence found on the Android 7.0 Nougat AOSP. A few lines of code on the mobile operating system directly referenced Andromeda, with an anonymous source revealing that there are some users testing the early builds of the hybrid operating system on the tablet.

The reason behind using the Nexus 9 to test Andromeda is not clear. However, it is largely known that the idea behind merging Android and Chrome OS was so that Android would become better suited to power laptops and similar machines such as the 2-in-1 laptop/tablet hybrid devices.

Despite Lockheimer possibly hinting that Andromeda will be announced on Oct. 4, along with reports that Google is already testing the merged operating system, users should not get ahead of themselves. It is still unclear if there will be a demonstration of Andromeda at the upcoming event, or when the hybrid operating system will be ready for users to try out.

The unveiling of Andromeda could be Google's biggest surprise on Oct. 4, or it could just be a quick mention on the project. Nevertheless, the hybrid operating system represents what would be Android's biggest evolution, and that is something that users should look forward to.