Microsoft is officially jumping into the smart speaker market with the Cortana-powered Invoke by Harman Kardon. Set for release in the fall of 2017, the device will initially be capable of making and receiving calls via Skype, voice-controlled music playback and completing various tasks using Microsoft's personal digital assistant. But the company will also be taking a page from Amazon's Echo to expand its functionality through the use of 'skills' that developers can tap into to integrate their services.

Today Microsoft launched the Cortana Skills Kit in a public preview. The SDK will allow developers to create third-party 'skills' by creating a bot and publishing it to the new Cortana channel of the Bot Framework, meaning those who have already been busy with Microsoft's Bot Framework can reuse the same code. The Cortana Skills Kit will work across all devices where Cortana is available, which includes Windows 10 devices, Android, iOS and Cortana powered speakers --- it's US only for now, however.

Early partners include Expedia, Capital One, Domino's iHeartRadio, TuneIn, OpenTable, weather notification service Dark Sky, and others. Microsoft has posted a complete list here. These are still in early preview stage, and many more are expected to arrive in the coming months.

In addition to Harman Kardon, HP is also creating a Cortana-powered speaker, while Intel will be creating a reference platform for other hardware vendors to create their own Cortana-powered devices.