The site http://opendataforafrica.org/ throws a warning that Opera isn't supported--due to the fact that the Ajax Minifier produces non-ES5.1 spec compliant code that throws in current versions of Opera.
 
To reproduce, go to opendataforafrica.org and click past the browser warning sign. In the console (either Dragonfly or the Error Console), you'll see:
 
[June 9, 2026 10:15:36 PM] JavaScript - http://opendataforafrica.org/_cassette/scriptbundle/Js/jQuery_bae36a9c51cd203132478b8e6a47bc6684efcb77
Linked script compilation
Syntax error at line 24 while loading: expected ')', got keyword 'in'
or(i.isArray(t)||(t in e?t=[t]:(t=i.came
 
The offending line is here: if(e){for(i.isArray(t)||(t in e?t=[t]:(t=i.camelCase(t),t=t in e?[t]:t.split(" "))),s=0,c=t.length;s<c;s++)delete e[t[s]];if(!(r?st:i.isEmptyObject)(e))return}}
 
Minified from,
 
(from jQuery 1.7.1, https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.js):
if ( thisCache ) {
 
// Support array or space separated string names for data keys
if ( !jQuery.isArray( name ) ) {
 
// try the string as a key before any manipulation
if ( name in thisCache ) {
name = [ name ];
} else {
 
// split the camel cased version by spaces unless a key with the spaces exists
name = jQuery.camelCase( name );
if ( name in thisCache ) {
name = [ name ];
} else {
name = name.split( " " );
}
}
}
 
for ( i = 0, l = name.length; i < l; i++ ) {
delete thisCache[ name[i] ];
}
 
// If there is no data left in the cache, we want to continue
// and let the cache object itself get destroyed
if ( !( pvt ? isEmptyDataObject : jQuery.isEmptyObject )( thisCache ) ) {
return;
}
}
 
12.6 of ES5.1 says that the "NoIn" production should be used for the "head" of a for-loop, so the parser is just being spec compliant here & following the grammar. We added as part of ES5.1 work and getting test262 to pass. Unfortunately other browsers aren't spec compliant in this matter.
 
It would be nice if the Ajax Minifier could produce ES5.1 compliant output. :)

    for(var hasAlert=("alert" in window), ndx=0; ndx " + ndx + "");
    }
    document.write("has alert: " + hasAlert + "");

    for(var hasAlert=("alert" in window), ndx=0; ndx < 5; ++ndx)
    {
        document.write("<h1>" + ndx + "</h1>");
    }
    document.write("<h2>has alert: " + hasAlert + "</h2>");