ZoneMinder

In reality, ZoneMinder is so much more than a single piece of software. It is actually an entire suite of apps that all work together to offer a comprehensive solution for home or business surveillance. You can use the software to record and analyze footage from any security camera or closed-circuit TV system. The software will work with a single camera or several. If you need multiple cameras spread across a wide area, this is the solution for you. The user interface for ZoneMinder is fully based on the web, and there are apps for both the iOS and Android platforms. That makes it easy to access the system from just about anywhere you might find yourself. One of the biggest problems with other security systems is that they require you to use their own cameras, which are generally extremely overpriced. You aren't locked into any particular camera set when you use ZoneMinder. You can use ZoneMinder with all cameras that use IP-based communications or analog recording. That means you can add functionality to the system via the cameras. For instance, you can use night vision cameras if you feel there is a threat in the night. You can use premium HD cameras if you need the sharpest resolution to see every tiny detail. The ZoneMinder software also gives you total control over bit of data that you generate while using the software. You not only own all of your data, but you can elect where you want it to be stored. For now, you can keep all your data secured on-site, and soon you'll have the option to take advantage of features that are enhanced by their utility through the Cloud. It doesn't really matter how big your surveillance system needs to be. It can be as simple as a single camera for your home's front door, or as complex as a whole series of cameras to protect your business while you aren't there. It can even be used by enterprise brands that want to use their own servers to support the software. You can load the software onto just about any machine, including something as small as a Raspberry Pi or something as large as an enterprise-grade server. The tools in the software make it easy to find what you want in a snap. Browsing through the software is highly intuitive, so it usually only takes moments to find what you need. The system is maintained by a professional team that is fully dedicated to keeping the software free.

Does not build cleanly on either RPi3s or FreeBSD, as of the end of first quarter 2019.

It kills the wifi on my LAN with 2 cameras. It's a pity because I finally got it installed.

If you are bothered with false alarms from the motion detection feature of a camera, take a look at AI-HomeGuard (on sale at Amazon). The AI based PC software will eliminate any false alarm without missing positive events. It records detected objects (person, car, etc.) as an NVR, and you can search and play the videos from a smart phone or iPad.