diff --git a/eo/doc/mainpage.html b/eo/doc/mainpage.html
index 61d422b0..5a36124a 100644
--- a/eo/doc/mainpage.html
+++ b/eo/doc/mainpage.html
@@ -73,8 +73,9 @@
             <p>Recent versions of EO have been tested on the following
             platforms:
             <ul>
-              <li>Linux with GCC 3.x and 4.x</li>
-              <li>Windows/CygWin with GCC 3.3.1 (cygming special).
+              <li>Linux-x86 with GCC 3.x and 4.x</li>
+              <li>Linux-x86_64 with GCC 3.x</li>
+              <li>CygWin (Windows XP) with GCC 3.3.1 (cygming special).
               <li>Win95/NT with VC++ 5.0 and Borland Builder. Makefiles and
                 projects files are provided.</li>
             </ul>