Well, it seems (to me) that I have discovered a new Turtle-type fractal.

I had to prepare a project for my LISP exam consisting of implementation of the Turtle graphics primitives in LISP and some examples of fractals.
I've tried to write by heart the code for the trivial tree and by a lucky mistake I've found it.

Here's a snapshot of the XLISP version:

The Brain fractal for n=12 iterations.

You can have the original XLISP sources [lost!] for MSDOS (unfortunatedly I was not able to compile it for LINUX) and the xlisp.exe binary (i.e. the LISP environment).
I have carefully checked it for viruses -- it seems to be clean.

Running it it's simple: unpack the archive to some directory and (from MSDOS or DOSEmu under Linux) type the following command:

xlisp brain.lsp

If you want to compile the binary by yourself, you can get the whole XLISP package.

I wanted to have a Java version of it.
Hence I have hardly worked on modifying the CLSFractal class from Sun's JDK.
After two days of hard programming I discovered that I did not have to modify the class itself but it was enough to modify the parameters for this class such that for a n=12 to have the same shape.
This is a paradoxical conclusion because the algorithm's primitives for moving the turtle are not the same. (You can convince yourself of that by running my LISP version with n running in {1,...,4} and the Java version for the same n)

You may compare the LISP version with the Java version

Click this applet to see how it is generated!
Here you have the (java) source of CLSFractal provided by JDK 1.0