- corrected typo

html/tutorial/index.html

@@ -93,7 +93,7 @@ Javadoc).
 <h2>Preparation</h2>
 
 <p>This preparation phase, is common to all tutorials (but the second
-  one which only requires a wen browser).</p>
+  one which only requires a web browser).</p>
 
 <p>For running the alignment <abbr>API</abbr>, you must have a Java
   interpreter available. We will call it <tt>java</tt>. For compiling