OpenEuphoria

Then

l_flags &= " -mno-cygwin -lws2_32 -lcomdlg32" 

should become

l_flags &= " -mno-cygwin -lws2_32 -lcomctl32" 

l_flags &= " -mno-cygwin -lws2_32 -lcomdlg32" 

should become

l_flags &= " -mno-cygwin -lws2_32 -lcomctl32" 
 
if not con_option then 
        l_flags &= " -mwindows" 
end if 

unless you want to have the nasty console opening on every windowed application.

I am not quite sure if lines 417-419 in "buildsys.e"

if not con_option then 
        c_flags &= " -mwindows" 
end if 

are useful at all.