You'll have to use the "Reset Tutorial" button to see all the changes.
The biggest change is that you can now click on an expression to highlight it. To see what I mean, try clicking on stuff in the tutorial.
But the coolest part is that the highlighting understands boxes. Try inputting this:
box foo = 5
foo + 10
box foo = 20
foo + 30
Now try clicking on the 1st or 2nd "foo". Then try clicking on the 3rd or 4th "foo". And it's so smart, it can even differentiate local variables (which is non-trivial because Nulan compiles top-level forms, like Arc):
Once again, try clicking the 1st or 2nd "foo", then the 3rd or 4th "foo".
It's also smart enough to know that the "." syntax is a string, even though it looks like a symbol:
box foo = []
foo.bar <= 5
foo.bar
So, obviously this isn't just a simple name search. The nice thing about this is, because Nulan uses boxes, it will only highlight the symbols that evaluate to the same box.
Imagine a search/replace function that operates on boxes rather than symbols: you'll be able to find/rename exactly the right symbols, rather than symbols that happen to have the same name.