Here's a quick interview video from the 2016 Cinegear Expo with company High Sight. They offer a few different models of Cable Cams. These tools are often easier to use than Drones (not to mention quieter), offers longer run time, can fly through tight spaces, shots are easily repeatable, and pretty much legal to use in most cases Drones are not allowed.
One feature that High Sight Cable Cams offer is a setting A/B end points allowing you to focus on camera tracking and not worrying about reaching the end of your line. Below is a video example produced using the High Sight Cable Cam.
Varavon has been teasing their Wire Cam (cablecam) product for a few years now, but they state they will officially open sales starting next week. We'll just have to wait to see. Here's the latest video demo using the BirdyCam2 gimbal placed below the Wire Cam.
The Wire Cam can be used with any 3 axis gimbal stabilizer, or with your camera mounted directly (though it won't be stabilized). You can already find a parts list, more video samples, and additional information at the Wire Cam product page (click here).