LG Zaum bitless bridle
I just came back from a trip to Germany and stumbled upon a very interesting bitless bridle design, which distributes pressure onto poll, nose and chin. It works especially well for fine communication with a light hand i.e. in dressage, but it's also popular with endurance riders in Europe. Its name is LG zaum bitless bridle system, LG bridle or Gluecksrad.
I have been using a Dr Cook Bitless Bridle before with my mare, and it worked for most things we did. My arab just didn't like that the release is so slow; she wants freedom of her head, which I can now get easily with the LG (just a very light contact is necessary to get her to round up - I ride dressage).
I have used a halter and indian bosal besides the Dr. Cook, but the LG zaum is by far the best, because the most precise. It feels just like a bitted bridle.