diff -up asymptote-1.63/settings.cc.orig asymptote-1.63/settings.cc
--- asymptote-1.63/settings.cc.orig	2009-02-17 21:55:36.000000000 -0500
+++ asymptote-1.63/settings.cc	2009-02-18 10:16:17.000000000 -0500
@@ -80,11 +80,11 @@ const bool haveglut=false;
 bool msdos=false;
 const char *HOME="HOME";
 const char pathSeparator=':';
-string defaultPSViewer="gv";
+string defaultPSViewer="evince";
 #ifdef __APPLE__
 string defaultPDFViewer="open";
 #else  
-string defaultPDFViewer="acroread";
+string defaultPDFViewer="evince";
 #endif  
 string defaultGhostscript="gs";
 string defaultPython;