Nottingham 3 is an update of a clone of Notational Velocity. It's explicit about its debt: "In the spirit of Notational Velocity, Nottingham is an elegant notepad for macOS. Designed to be lightweight and easy to use, it's a breath of fresh air perfect for storing whatever is on your mind." But the claim is that "Version 3.0 is completely rewritten from the ground up in Swift 3 to take full advantage of macOS's newest features and to lay a solid foundation for future improvements." And it promises to be fast: "Lightning-fast search across even the largest library of notes." I wonder what the "largest library" is. 100,000 notes, 1,000,000? It would be nice to know.
It now also claims to be able to do "wikilinks." But this is at best a half-truth. It can link to existing notes, and it seem to be able to keep track of the name-changes of those notes, but it cannot create new notes from a typed link. Notational Velocity and nvALT can't do that either (and in addition they cannot keep track of name-changes), but they are free. Nottingham costs $14.95 (though you can try it out for free).
I dislike the name. Searching for "Nottingham" gets you a lot about a city in in the East Midlands of England, getting to the application is harder. It's a complaint about some applications I have for a long time. Try "Brainstorm," for instance!
1. It does not do so reliably, however. There seems to be a problem with the program. I have deleted it again from my machine!
2. Actually nVALT can create a new link from an expression enclosed in double square backets. Clicking on an expression enclosed in double brackets, puts it into the search window, pressing enter creates the topic. nvALT does not, however, keep track of name changes.