This is splice.org.uk, a hosting co-operative. It's run by a group of friends who rent a dedicated server from Bytemark and run Xen on it, with one virtual machine each. We also have a shared VM for running common services.
The current splicers are:
Due thanks must also go to Dominic and Spiny for supplying our Nagios monitoring.
Splice used to run its own SSL certificate authority, but that's no longer necessary in an age where proper CAs give out certificates for tens of pounds, so we wound ours up (the paranoid may view a PGP-signed confirmation of this).
David North, February 2013