--- asymptote-2.21/settings.cc~	2012-10-10 21:36:00.000000000 +0400
+++ asymptote-2.21/settings.cc	2012-12-27 06:03:11.621180534 +0400
@@ -90,11 +90,11 @@
 string HOME="HOME";
 string docdir=ASYMPTOTE_DOCDIR;
 const char pathSeparator=':';
-string defaultPSViewer="gv";
+string defaultPSViewer="xdg-open";
 #ifdef __APPLE__
 string defaultPDFViewer="open";
 #else  
-string defaultPDFViewer="acroread";
+string defaultPDFViewer="xdg-open";
 #endif  
 string defaultGhostscript="gs";
 string defaultDisplay="display";