For years, Fusion software has been popular for complex compositing, including being used on more than 1,000 major Hollywood feature films. Developed by eyeon Software, that company has now been acquired by Blackmagic Deisgn.
You can get some idea of the capability of eyeon Fusion by visiting the eyeon web site and looking at some videos. If you have used a timeline in an NLE, then you might think this is an easy way to add layers and do effects. However when you start doing anything complicated in a timeline, such as add a few clips, then add a few effects to each clip, with each effect having multiple parameters to adjust, it can get complex very quickly.
Fusion from eyeon Software solves this complexity by using nodes. With nodes, each thing to do is a little node, and you have a whole collection of effects you can just connect up to do anything you like. When you want to adjust anything in a shot, you just check on the node and adjust it.
Fusion also has a large palette of effects, such as motion graphics, a tracker, color correctors, particles, keyers, plus even paint with rotoscoping and onion skinning. The environment is full 3D and there are 3D tools and simulations.
Blackmagic Design has not yet announced pricing and marketing strategy, but it's worth noting that the company purchased DaVinci Resolve and now gives away a version of the Resolve product.