How to install MJ12node (the Majestic-12 distributed crawler) on Debian 7 x64

Get the package prepared by refic here: https://www.majestic12.co.uk/forum/viewtopic.php?t=4423
As of today (22 December 2013), the latest appropriate version (LEGACY) can be obtained directly using:
wget http://mono.mj12.fi/mj12node-bundle/mj12node-linux-v1710-bundle-32bit-mono-3.2.1-LEGACY.tgz

Then you need to install “some” (there’s quite a bunch of them actually, better run this in screen if you’re on a remote connection) 32 bits libraries:
(NB: unlike the other parts which should be run as the user dedicated to MJ12node, this part needs to be run as root/sudo)
dpkg --add-architecture i386
apt-get update
apt-get install ia32-libs

And as of Debian 7 that should be all (I think before that you also had to install ia32-libs-gtk, so if you are on an earlier version and the above isn’t enough for your node to work, you can try adding this package too). Now back to the archive you downloaded: unpack it then run it:
tar xf mj12node-linux-v1710-bundle-32bit-mono-3.2.1-LEGACY.tgz
cd MJ12node
./run.sh

Now this is just a first run. If everything works, press ‘s’ to activate the webserver control interface. Then access your machine in your browser on port 1088 (http://your_machine_s_IP:1088), and configure it, notably enter your account information in the option panel and don’t forget to save. At the moment there’s a bug in the software: once you’ve entered your login details, it won’t be able to fetch work until the node is restart it. So go to tools and restart your node. Or, if you don’t want to wait the standard 30 seconds imposed for a restart, shut it down and then restart it manually (./run.sh in console again, once the node did shut down). This second option is my favorite, notably because it’s the occasion to relaunch the node via screen this time (it’s not a daemon so you need to run it in screen).

Well, that’s about it. If you don’t know about screen, here are the commands:
apt-get install screen (shouldn’t be needed, but in some light distributions it’s missing!)
screen
./run.sh

Another remark: the web interface can be manually opened and closed from the console by pressing respectively ‘s’ and ‘t’. You can also configure the node to always run the web interface, with a password, on a custom port, etc., via the options.