It comes with a small grappling hook, too, true believers!
DIY railguns are a thing, too, although the end results aren't as lethal, or large. Take this Spider-Man-themed project by YouTuber AnselmoFanZero. The setup combines a small electromagnetic railgun with a laser (for aiming, not for melting), and a grappling hook assembly.
The power plant is a 350W capacitor bank, which is capable of putting out 100 joules of energy. The demo shows the unit firing some sort of small projectile, then using the same railgun to launch the grappling hook. There's a winch motor in there, too, to pull the hook back in.
If an engineering enthusiast can pull this kind of gear off in his house, just imagine the kind of shenanigans being cooked up by the friendly folks over at DARPA...
[Source: Hack A Day]