Em 19 de setembro de 2012, Biagio Salerno escreveu: (...) Right now I am focusing on dynamic panel data, especially on Arellano-Bond estimators. I used gretl for the last few months, and it worked great. Still, after i downloaded and installed Mountain Lion on my mac (which does not incorporate X11 anymore, so i had to download XQuartz), Gretl would not run anymore. Could you please help me with this matter? Dear Biagio, I had exactly the same problem when I installed Mountain Lion. I solved my problem just reinstalling Gretl (delete the version you have and install a new one).