By the end of the year, you'll be able to tell your Windows 10 PC "Hey Cortana, open Alexa" and talk to Amazon's personal assistant. Or if your Echo is in earshot, you'll be able to tell it "Alexa, open Cortana" to talk to Microsoft's assistant instead. Microsoft and Amazon are working together to ensure that their voice-driven digital assistants will be able to work together in a surprising collaboration.

Both companies have reach in areas the other does not; Microsoft says that there are some 145 million monthly active Cortana users on Windows 10 PCs, while Amazon has found success selling its Echo speakers into living rooms and bedrooms. With this partnership you'll be able to take advantage of Alexa's easy online shopping from your PC or Cortana's stronger calendar integration on your sofa.

The integration will, at least initially, be a little clunky, as you'll have to ask one voice assistant to start up the other before you can use it. Long term, Amazon CEO Jeff Bezos says that he hopes this won't be necessary and that each device's primary assistant will be able to defer tasks to the secondary assistant as appropriate. The collaboration was Bezos' idea. He approached Microsoft CEO Satya Nadella in May last year to suggest bringing the two voice agents together, and Nadella agreed.

Both men were concerned that if their digital agents didn't cooperate in this manner, then their usage would be reduced. The thought was, it's better to offer access to as many digital assistants as possible so that customers can take advantage of the relative strengths of each offering.

Bezos said he hasn't approached Apple or Google to ask if they want to integrate, but he'd welcome such interoperability. Nadella similarly said that he hoped the two companies would be inspired by Amazon and Microsoft's partnership.

While the partnership is likely to be good for both users of Windows 10 and the Echo, it does somewhat call into question Microsoft's plans to have Cortana-powered speakers such as the Harman Kardon speaker revealed last year. With full access to Cortana's capabilities, one might as well just buy an Echo.