I was going to add Oleg's and my version of the dragon curve to the
rosetta code page, but I am not seeing the confirmation code graphics
so I can not register nor post anonymously there.

If someone else could add an entry for J, I would appreciate it.

Also, if someone could identify the name of the host which provides
the confirmation code graphics, so I can check my firewall settings, I
would appreciate it.

Thanks,

-- 
Raul

P.S. The rosetta code page for dragon curve is

   http://rosettacode.org/wiki/Dragon_curve

and here is my proposed entry:

=={{header|J}}==

 require 'plot'
 start=: 0 0, 1 0,: 1 1
 step=: ],{: +"1 (2 2$0 _1 1 0) +/ .*~ |[EMAIL PROTECTED]: -"1 {:
 plot<"1|:step^:12 start

In english: Start with an L shaped geometry.  For each step of
iteration, retrace that geometry, but oriented 90 degrees about its
original end point.  To show the curve you need to pick some arbitrary
number of iterations.

Any L-shaped set of points is suitable for start.  (For example,
-start+123 works just fine though of course the orientation and
coordinates will be different.)

For a more colorful display, with a different color for the geometry
introduced at each iteration, replace that last line with:

 ([:pd[:<"1|:)every'reset';|.'show';step&.>^:(i.16)<start
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