They are a provider of hosted dedicated servers, colo and virtual machines (with or without server management services), based in Germany.

They're really inexpensive, which explains their niche popularity...

They're very big, not just a niche. Also reliability / support is not necessarily always so much worse than some higher price solutions.

Aye, they seem to have a very good reputation for a cheaper provider. I've not used their services myself though.

They're a German Server/Webspace ISP - see www.hetzner.de/en

Not just German actually, they (Hetzner Online AG) have also got a subsidiary in South Africa ... http://www.hetzner.co.za/

ik,r

But since this seems to be affecting only the main/german division, i didn't bother to mention them.