Facebook Home is not an operating system but a skin that can be installed on top of Google's Android OS.

As expected, Facebook premiered its own tailor-made Android skin, Facebook Home, on a new handset from HTC today, the HTC First, at a press event held near the company's headquarters in Palo Alto, California.

The Facebook-centric mobile OS is a modified version of Android's mobile operating system, crafted to feature Facebook first, much as Amazon did with the Kindle Fire. 

Facebook CEO Mark Zuckerberg stressed that the new platform brings people, i.e. Facebook, to the forefront of users' smartphone experience, rather than apps. Facebook is always the focus here: users will first see "Home," a streaming feed from Facebook with status updates and images. Notifications and "chat heads" are integrated into Facebook Home, allowing you to communicate quickly with contacts without needing to open an app or leave the one you're using.

Facebook Home will available as a free download from the Google Play store ...
... and setting it as your default launcher will turn any compatible Android phone into a "Facebook phone."

The HTC First showcases Facebook's new OS on a 4.3-inch display. The handset can be pre-ordered through AT&T starting today for $99.99 and will be available April 12. The device is running Android 4.1 (Jelly Bean) with Facebook Home and is powered by a Qualcomm Snapdragon™ 400 processor with dual-core CPU.

Though camera specs were not immediately confirmed following the press event, the HTC First is expected to feature a 5-megapixel rear camera and 1.6-megapixel front camera. These specs are rather minimal compared to the 13MP camera phones that are quickly becoming the new industry standard. However, 5MP actually makes quite a bit of sense for a phone and camera designed for primarily social photography taking and sharing.

The stories from your Facebook news feed will be displayed on the home screen.
Apps will still be accessible through an app launcher.

Facebook's Home will be available for other compatible Android devices, including the HTC One X, HTC One X+, Samsung Galaxy Note II and Samsung Galaxy S3, starting April 12. Home will also be available for the soon-to-be released HTC One and Samsung Galaxy S4. A tablet version is under way for a future release date.

Though Facebook was long-rumored to be making a true "Facebook phone," Zuckerberg consistently denied his company was going into the hardware business. The software move instead seems more in keeping with Facebook's major efforts toward expanding its mobile outreach. After significant updates to its mobile apps for both Android and iOS in the past year, the new OS takes Facebook's mobile efforts that much further.

So-called chat heads can be placed on top of any app screen and moved around ...
 ... to give you quick access to a conversation with your contacts.