Update README.md

README.md

@@ -18,7 +18,13 @@ License
 IWolfram is released under the GNU General Public License (GPL).
 
 
+About graphics
+---------------
 
+Currently, iwolfram has almost full supports for graphics when uses the original Wolfram's Mathematica kernel as the backend, and a very limited support when runs over the Mathics kernel. On the other hand, to generate image files, Wolfram's requires that the user have a graphic terminal open on the server. Worst, if a graphic server is not available, a call to a graphic command make the iwolfram kernel to crash.  If we run the jupyter server in the same machine we are running the front end this is not a problem, but it could be if the server runs in a remote machine. To overcome this issue, a workaround is to use the xvfb xorg kernel to simulate a graphic server. To do this, we need to install xvfb in the computer where jupyter is going to run, and establish 
 
+'xvfb-run -a -s "-screen 0 640x480x24"  /usr/local/bin/MathKernel'
+
+ as the the kernel backend.