They've taken the Meego OS and played around with it to make the Sailfish OS. A bit like Samsung have done in making Tizen.
They are based in Helsinki but also have an office in Hong Kong since they realise that Asia is where the growth is going to be.
Nokia wasted a very good opportunity with Meego. In my opinion it is a very good OS superior to WP8 and Android, I would guess superior to iOS as well but I don't have experience with iOS to make a comparison. It's nice to see that Meego will live on as Sailfish and perhaps will see the success it deserved.
Today Jolla announced that Android apps will now be able to run on Sailfish, giving them access to a large range of apps without the need to develop Sailfish apps right away.
Jolla are also building their own handsets. They have already sold out their first production run and are taking pre orders for the next run.
I hope they're successful.