On Thursday, Facebook is poised to unveil an HTC Android handset running custom software, making the social network the new mobile homescreen — or so a long-running series of rumors suggests. Reports of Facebook developing a branded handset with a smartphone manufacturer date back to 2010, but the few descriptions that have surfaced since have provided little information on the long-deferred device or its software. This time feels different. Not only are these rumors tied to a specific event explicitly devoted to mobile, but the last few days' leaks have been unusually detailed. Those details point in a direction that makes more sense than Facebook producing its own phone, and instead look like software that could work on any Android device. We're finally starting to get a sense of what Facebook will likely unveil later this week.

Either part or all of the smartphone's homescreen will be devoted to information from the user's Facebook account, according to similar reports from The New York Times and The Wall Street Journal. Core phone features such as the camera may directly integrate with Facebook, automatically storing and sharing pictures. Facebook's previously made stand-alone apps, including Messenger, may also be incorporated into the new software. The theory is that the more prominently Facebook is featured on the device, the more likely users will engage with the network.

Facebook's flagship phone will likely be a midrange HTC handset

The consensus is that Facebook's software will initially be featured on a specific phone. Rumors have long suggested a partnership between Facebook and HTC, the Android manufacturer with the longest history with Facebook, the most to gain, and the least to lose. Upcoming View recently revealed details of a mid-range HTC handset codenamed "Myst" that's likely to include the new Facebook software. The device will purportedly run Android 4.1.2, have a 4.3-inch, 720p display, and include 1GB of RAM, 16GB of storage, and a 5-megapixel camera. A leak earlier today suggests that the phone will officially be called "HTC First" and feature an iPhone-like body with three capacitive buttons.

But the custom software will also be capable of running on many Android devices, including those from Samsung, HTC, and Google. A leaked build acquired by Android Police confirms that the new software will likely be called "Home," and will change the homescreen's look, and add Facebook integration to major parts of the phone.

Facebook has already demonstrated the potential for this integration with its standalone apps. Messenger integrates standard text messages with Facebook’s messaging service, and also offers free VOIP calling in the US, Canada, and the UK. These are both likely to be prominent features in any coming device or software. Consumers are much more likely to utilize Facebook’s services when they’re at the core of a redesigned homescreen, rather than tucked into the corner of an existing app.

Facebook's software will go on many Android devices, but just how deep will it go?

Just how deeply Facebook's software will integrate into the operating system remains unclear. Early reports suggested that the software would integrate with the phone's contact list or even provide a platform for running HTML5 applications. However, these reports date from 2010 and 2011, and Facebook has since strayed from its focus on HTML5.

Many of the rumors surrounding the "Facebook phone" date from different points in the project's history, making it difficult to know which ideas are active and which have been discarded. The software project reportedly began in response to Google's Nexus program, shortly before the release of the Nexus One. In early 2011, a small partnership between HTC and Facebook resulted in the ChaCha and Salsa, two low-end devices that included a dedicated button to access the social network. Later that year, AllThingsD reported that the phone software project, codenamed "Project Buffy," was more heavily underway, with the first product likely arriving either in winter or spring of 2013.

Zuckerberg has said a Facebook phone "just doesn't make any sense"

Though a smattering of reports since then have detailed the project's progress, Facebook has steadfastly denied the rumors. As late as September 2012, when asked about the possibility of a Facebook phone, Mark Zuckerberg flatly told TechCrunch, "That's always been the wrong strategy for us." He later added that the idea of Facebook building a hardware device "just doesn't make any sense."

Thursday's announcement may simply be a modest, iterative evolution in Facebook's mobile strategy. But after years of buildup, that would be widely seen as a disappointment. If Facebook's phone efforts are as substantial as these rumors suggest, the social network's "new home on Android" could broadly embed the company's products into the Android operating system across a wide range of products. If Facebook can make an Android skin that customers want to use, the company would have a deep integration that no other social network could match. And if its services prove popular with enough users, Facebook's new flavor of Android will be something other smartphone manufacturers will have to contend with, too.