Let me reply to everything at once. I haven't seen N_Ox's emails, just Tommaso's.
The port complained that you did not have the 10.3.9 SDK. So the solution is to install the 10.3.9 SDK. This is part of the Xcode installer. I forget whether it's there by default, but regardless, it needs to be installed now. Customize the Xcode installation and you should see it.
You would not have been able to get this far with the MacPorts installation if you did not already have Xcode installed. Perhaps you had an older version of Xcode? If so, that is usually a fairly major problem, so it's a good idea to get 2.4.1 installed now.
Let us know what errors, if any, you still have after upgrading Xcode and installing the requisite SDK.
Sorry for the late reply, I was out to dinner. :) I have downloaded and installed Xcode 2, the SDK was included in the installer, so after the upgrade I managed to install libsdl-framework just with this command: sudo port install libsdl-framework And nothing else. So, for the people who has the same problem, install Xcode 2 :) (in the .dmg there is also a directory called "Packages" with the various SDK and libraries, so I think it's possible to install them singularly). Tommaso