diff --git a/src/JRex.java b/src/JRex.java
new file mode 100644
index 0000000..20fad27
--- /dev/null
+++ b/src/JRex.java
@@ -0,0 +1,35 @@
+
+import java.awt.Color;
+import javax.swing.UIManager;
+import jrex.ui.MainFrame;
+
+/*
+ */
+/**
+ * Main class.
+ *
+ * @author Mark George <mark.george@otago.ac.nz>
+ */
+public class JRex {
+
+	public static void main(String args[]) throws Exception {
+		UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
+
+		// set dark theme if arg exists
+		if (args.length > 0 && "dark".equalsIgnoreCase(args[0])) {
+			UIManager.put("control", new Color(50, 50, 50));
+			UIManager.put("nimbusBase", new Color(60, 60, 60));
+			UIManager.put("nimbusBlueGrey", new Color(60, 60, 60));
+			UIManager.put("nimbusFocus", new Color(90, 90, 90));
+			UIManager.put("nimbusLightBackground", new Color(70, 70, 70));
+			UIManager.put("text", new Color(230, 230, 230));
+		}
+
+		java.awt.EventQueue.invokeLater(new Runnable() {
+			@Override
+			public void run() {
+				new MainFrame().setVisible(true);
+			}
+		});
+	}
+}