The command-line tool runs in headless mode by default, so it will

work on a Linux console, e.g.  The JUnit tests will too, though 'ant
check' still fails because we don't sneak the -Djava.awt.headless=true
into the process early enough.

source/org/thdl/tib/input/TMW_RTF_TO_THDL_WYLIETest.java

@@ -43,6 +43,12 @@ public class TMW_RTF_TO_THDL_WYLIETest extends TestCase {
 	}
 
     protected void setUp() {
+
+        // Runs on Linux/Unix boxes without X11 servers:
+        System.setProperty("java.awt.headless", "true");
+        // FIXME: ant check still fails because it doesn't see the
+        // above property early enough.
+
         // We don't want to use options.txt:
         ThdlOptions.forTestingOnlyInitializeWithoutDefaultOptionsFile();
         // We do want debugging assertions:

source/org/thdl/tib/input/TibetanConverter.java

@@ -51,6 +51,10 @@ public class TibetanConverter implements FontConverterConstants {
     /**
      *  Runs the converter. */
 	public static void main(String[] args) {
+
+        // Runs on Linux/Unix boxes without X11 servers:
+        System.setProperty("java.awt.headless", "true");
+
         System.exit(realMain(args, System.out));
     }