Does anyone remember the days when Facebook’s gaming ecosystem was dominated by Zynga? The social network continued to extend its reach in the gaming sector with Wednesday’s announcement of the release of a software-development kit for the Unity game engine.

The new SDK was announced at Unity’s Unite developers’ conference in Vancouver, British Columbia, and Facebook said in a post on its developer blog that its goal is to ease the process for Unity developers seeking to integrate with the social network.

Facebook said Unity developers can continue to write in C# and add social gaming experiences on all platforms, adding that three developers have already integrated the new SDK: Cmune with UberStrike, Madfinger with Shadowgun: Deadzone, and Nival with King’s Bounty: Legions.

Facebook-owned cloud-application platform Parse also announced at Unite that it will release a plugin for Unity that will extend the Parse back-end to web and mobile Unity developers, allowing them to store data, authenticate users, and implement advanced back-end features such as saving high-score data, saving game states for continuous play, and dynamically enabling and disabling a/b testing.

The social network said in its developer blog post:

The number of active Facebook users with Unity installed more than tripled in the first half of 2013, and today, more than 90 million monthly active users have Unity installed on the Web. Facebook has a relevant and engaged audience of gamers that mobile developers can reach by publishing their games on Facebook, and the SDK makes bringing a mobile game to Web as simple as writing one line of code. By filling out a few fields in the developer app and giving us the URL of your game object, you can bring your mobile game to a whole new audience of avid gamers on Facebook. Madfinger used the SDK to bring its mobile game, Shadowgun: Deadzone, to Facebook.com, opening up a new growth platform for the game with minimal effort.

As more graphics-rich Web games come to Facebook.com, players want to stay immersed in the game experience while connecting with friends, and the SDK helps you do that. We’ve built native Unity dialogs for inviting friends, requests, and sharing, so people can stay in full-screen mode when they interact with social features, creating a richer, smoother Web game experience for players.

We’re also helping more people find and play Unity games on Facebook by driving discovery of the Unity player with a custom install flow for the Unity plug-in.

Readers: Do you play any Unity games?