So much for the speculation about what the word 'join' meant.

It's now been confirmed that RIM has acquired Swedish UI specialist TAT in a deal said to be worth tens of millions of dollars.

The speculation kicked off when RIM CTO wrote a blog post entitled "RIM welcomes TAT", although quite why he couldn't have managed "RIM buys TAT" is another matter entirely.

"Today we're very excited as we are announcing that we're taking a huge leap towards our vision to help create a full user experience for a great line of devices and products.

"Today TAT has agreed to become a part of Research in Motion," the company says on its website.

It added, "Of course we will honour our current agreements and service our existing customers and have taken all the necessary steps to keep the two commitments separated."

I drew a map of Canada

Headquartered in Sweden, with offices in Malmo and Gothenburg, The Astonishing Tribe also has offices in San Francisco, Seoul, Tokyo and Taipei.

TAT has around 175 staff and is reported to be looking to make additional hires to support its new focus on RIM's PlayBook tablet and BlackBerry smartphone range.

Its recent work includes research on how gestures, haptics and stereoscopic 3D could improve user interfaces

[source: TAT]