Tomorrow is a big day in the smartphone operating system market as Finnish startup Jolla Ltd. will unveil its new MeeGo-based OS and user interface at an event in Helsinki. (See One Giant Leap for MeeGo .)

The company will reveal its new Sailfish OS and Jolla user interface on Wednesday morning at the two-day Slush conference, which brings together startups from Northern Europe and Russia.

The event will mark the revival of the work Nokia Corp. started on the MeeGo operating system before it ditched the platform in favor of Microsoft Corp.'s Windows Phone OS. Indeed, Jolla (which means a small sailboat in the Finnish language) was founded by a band of former Nokia employees who worked together on Nokia's N9 smartphone and the MeeGo OS. (See Nokia Refugees Revive MeeGo.)

Details are scarce about the Sailfish OS and new user interface, which is why tomorrow's announcement is eagerly anticipated. And while Jolla will reveal the OS and the user interface specifications, the startup has not yet specified the launch date for a device running the Sailfish OS.

But here's what we do know about Jolla and Sailfish so far:

• There will be three parts to Jolla's business: It will manufacture smartphones in order to lead the Sailfish ecosystem; it will license the OS to other device original equipment manufacturers (OEMs); and it will enter into revenue-sharing deals for the services it plans to introduce for Sailfish devices.

• The company is headquartered in Helsinki and has an R&D facility in Tampere, Finland, but it recently established an industry alliance in Hong Kong to develop a version of Sailfish for the Chinese market. (See Startup Jolla Revives MeeGo in China .)

• Jolla has partnered with China's largest phone retailer, D.Phone Group.

• Sailfish is not exactly MeeGo, but based on MeeGo. It builds on the work of open-source programs including the Qt Project and Mer Core.

• Sailfish is not just for smartphones; the OS is also designed for set-top boxes, TVs and tablets.

• In October, Jolla COO Marc Dillon took over the CEO job from Jussi Hurmola, who is now focused on Sailfish strategy. Dillon was previously Nokia's principal engineer for MeeGo.

The big questions for Jolla that ought to be answered tomorrow are: How will this new OS be different from Apple Inc.'s iOS, Google's Android, Windows Phone and other alternative open-source platforms? And how will Jolla attract developers to create compelling applications and mobile operators to back its devices?

For more

• Startup Develops MeeGo Smartphones
• Euronews: MeeGo Is Reborn

— Michelle Donegan, European Editor, Light Reading Mobile