I started npmjs.eu in the times where registry.npmjs.com wasn't all that stable. Back then, having an European mirror was making actual difference in availability, latency and bandwidth, thus making installs faster and more reliable.
A lot has changed since then. The registry went through a few significant architecture changes, the most important one, in my opinion, being put behind a CDN. That means that there isn't much difference in installation times anymore, no matter the geographical location. At the time of writing this (November 2014), since February 2014 there hasn't been a month with less than 99.5 % uptime, and we've even seen two months with 100 % uptime. This is impressive, and I'd like to take a moment to thank the npm, Inc team for such an impressive work in keeping the service we all rely on so stable.
As time passed, it became clear to me that maintaining this mirror is pointless and time-consuming, and admittedly, I sucked at it. I would like to apologize the community for that.
It's time for npmjs.eu to shutdown. From now on (and for the foreseeable future), all requests will return 301, pointing to registry.npmjs.com.
— with love, Maciej Małecki