this short HN thread resonates with the intuition of jude1 being stalled, it's last optimistic comment points to an orphaned comment in the big list above
It's certainly not active but perhaps could be revived now that the patents have expired (filed in 2001 so expired last year).
On the surface it's just a very optimized 256-ary radix trie. I think it would take some software archeology to determine if there was more to it than that and if it's assumptions still hold on todays processors.
Does it need to be active? It's done and it works.
It's not written in an highly unstable language. The safety of every bridge you drive over was probably partially validated using fortran numerical code from the 1980s.
Point being: a project needs updates to remain useful in contemporary contexts. code that happily built -Wall, pedantic, error... in April 2002 may fail miserably in today's tool chain.
plus it may not benefit from contemporary advances in silicon architecture, etc.
As someone with a degree in contemporary arts who switched to programming I humbly disagree with this statement.
Jokes aside, it took me quite a bit of trial and error to figure out that you are (probably) referring to Adaptive Radix Trees. Because "art tree" doesn't exactly give useful results.
On the surface it's just a very optimized 256-ary radix trie. I think it would take some software archeology to determine if there was more to it than that and if it's assumptions still hold on todays processors.