diff --git a/harmony-tests/run.sh b/harmony-tests/run.sh
index ec27881..ff604bd 100755
--- a/harmony-tests/run.sh
+++ b/harmony-tests/run.sh
@@ -15,7 +15,7 @@ SUCCEED_PASS=0
 SUCCEED_FAIL=0
 
 for f in harmony-tests/succeed/*.js ; do
-    ./njs -H -f $f >/dev/null 2>&1
+    ./njs -f $f >/dev/null 2>&1
     if [ $? -eq 0 ]; then
         SUCCEED_PASS=$(($SUCCEED_PASS + 1))
     else
@@ -35,7 +35,7 @@ FAIL_RESOLVE_PASS=0
 FAIL_RESOLVE_FAIL=0
 
 for f in harmony-tests/fail-resolve/*.js ; do
-    ./njs -H -E "Narcissus.resolver.resolve(Narcissus.parser.parse(snarf('$f')),Narcissus.interpreter.globalStaticEnv)" >/dev/null 2>&1
+    ./njs -E "Narcissus.resolver.resolve(Narcissus.parser.parse(snarf('$f')),Narcissus.interpreter.globalStaticEnv)" >/dev/null 2>&1
     if [ $? -eq 0 ]; then
         FAIL_RESOLVE_FAIL=$((FAIL_RESOLVE_FAIL + 1))
         FAILURES="$FAILURES $f"
@@ -55,7 +55,7 @@ FAIL_EXECUTE_PASS=0
 FAIL_EXECUTE_FAIL=0
 
 for f in harmony-tests/fail-execute ; do
-    ./njs -H -f $f >/dev/null 2>&1
+    ./njs -f $f >/dev/null 2>&1
     if [ $? -eq 0 ]; then
         FAIL_EXECUTE_FAIL=$(($FAIL_EXECUTE_FAIL + 1))
         FAILURES="$FAILURES $f"
diff --git a/lib/jsdefs.js b/lib/jsdefs.js
index 680bb4f..70cd5a1 100644
--- a/lib/jsdefs.js
+++ b/lib/jsdefs.js
@@ -54,13 +54,16 @@
 
     var narcissus = {
         options: {
-            version: 185,
             // Global variables to hide from the interpreter
             hiddenHostGlobals: { Narcissus: true },
             // Desugar SpiderMonkey language extensions?
             desugarExtensions: false,
             // Allow HTML comments?
-            allowHTMLComments: false
+            allowHTMLComments: false,
+            // Allow non-standard Mozilla extensions?
+            mozillaMode: true,
+            // Allow experimental paren-free mode?
+            parenFreeMode: false
         },
         hostSupportsEvalConst: (function() {
             try {
@@ -374,29 +377,6 @@ Narcissus.definitions = (function(hostGlobal) {
         return mixinHandler(redirect, catchall);
     }
 
-    function mirrorHandler(target, writable) {
-        var handler = makePassthruHandler(target);
-
-        var defineProperty = handler.defineProperty;
-        handler.defineProperty = function(name, desc) {
-            if (!desc.enumerable)
-                throw new Error("mirror property must be enumerable");
-            if (!desc.configurable)
-                throw new Error("mirror property must be configurable");
-            if (desc.writable !== writable)
-                throw new Error("mirror property must " + (writable ? "" : "not ") + "be writable");
-            defineProperty(name, desc);
-        };
-
-        handler.fix = function() { };
-        handler.getOwnPropertyDescriptor = handler.getPropertyDescriptor;
-        handler.getOwnPropertyNames = getPropertyNames.bind(handler, target);
-        handler.keys = handler.enumerate;
-        handler["delete"] = function() { return false; };
-        handler.hasOwn = handler.has;
-        return handler;
-    }
-
     /*
      * Mixin proxies break the single-inheritance model of prototypes, so
      * the handler treats all properties as own-properties:
@@ -721,7 +701,6 @@ Narcissus.definitions = (function(hostGlobal) {
         isNativeCode: isNativeCode,
         apply: apply,
         applyNew: applyNew,
-        mirrorHandler: mirrorHandler,
         mixinHandler: mixinHandler,
         whitelistHandler: whitelistHandler,
         blacklistHandler: blacklistHandler,
diff --git a/lib/jsexec.js b/lib/jsexec.js
index d75c343..04c0111 100644
--- a/lib/jsexec.js
+++ b/lib/jsexec.js
@@ -86,14 +86,9 @@ Narcissus.interpreter = (function() {
           CONTINUE_SIGNAL = new InternalSignal,
           EXIT_SIGNAL = new InternalSignal;
 
-    function ExecutionContext(type, version) {
+    function ExecutionContext(type, strict) {
         this.type = type;
-        this.version = version;
-        // In Harmony, the global scope record is not exposed to the program.
-        if (type === GLOBAL_CODE && version === "harmony") {
-            this.scope = {object: globalScope, parent: null};
-            this.thisObject = globalMirror;
-        }
+        this.strict = !!strict;
     }
 
     function isStackOverflow(e) {
@@ -112,13 +107,13 @@ Narcissus.interpreter = (function() {
                 return s;
 
             var x = ExecutionContext.current;
-            var x2 = new ExecutionContext(EVAL_CODE, x.version);
+            var x2 = new ExecutionContext(EVAL_CODE);
             x2.thisObject = x.thisObject;
             x2.thisModule = x.thisModule;
             x2.functionInstance = x.functionInstance;
-            x2.scope = x.version === "harmony" ? { object: new Object, parent: x.scope } : x.scope;
+            x2.scope = x.strict ? { object: new Object, parent: x.scope } : x.scope;
             var ast = parser.parse(s);
-            if (x.version === "harmony") {
+            if (ast.hasModules) {
                 resolver.resolve(ast, new StaticEnv(x.staticEnv));
                 instantiateModules(ast, x2.scope);
             }
@@ -184,7 +179,6 @@ Narcissus.interpreter = (function() {
                 throw new TypeError("only works on scripts");
             return fint.getBytecode().toString();
         },
-        version: function() { return ExecutionContext.current.version; },
         quit: function() { throw EXIT_SIGNAL; },
         assertEq: function() {
             return assertEq.apply(null, arguments);
@@ -197,24 +191,7 @@ Narcissus.interpreter = (function() {
         return Proxy.createFunction(
             definitions.makePassthruHandler(val),
             function() { return val.apply(hostGlobal, arguments); },
-            function() {
-                var a = arguments;
-                switch (a.length) {
-                  case 0:
-                    return new val();
-                  case 1:
-                    return new val(a[0]);
-                  case 2:
-                    return new val(a[0], a[1]);
-                  case 3:
-                    return new val(a[0], a[1], a[2]);
-                  default:
-                    var argStr = "";
-                    for (var i = 0; i < a.length; i++)
-                        argStr += 'a[' + i + '],';
-                    return eval('new ' + name + '(' + argStr.slice(0,-1) + ');');
-                }
-            });
+            function() { return applyNew(val, arguments); });
     }
 
     var hostHandler = definitions.blacklistHandler(hostGlobal,
@@ -227,23 +204,14 @@ Narcissus.interpreter = (function() {
 
     var globalStaticEnv;                       // global static scope
     var moduleInstances = new WeakMap();       // maps module instance objects -> module instances
-    var global = Object.create(hostProxy, {}); // exposed global object (legacy)
-
-    // unexposed global scope record (Harmony)
-    var globalScope = Object.create(hostProxy, {});
-
-    // exposed global scope mirror (Harmony)
-    var globalMirror = Proxy.create(definitions.mirrorHandler(globalScope, true));
+    var global = Object.create(hostProxy, {}); // user global object
 
     function resetEnvironment() {
-        ExecutionContext.current = new ExecutionContext(GLOBAL_CODE, Narcissus.options.version);
+        ExecutionContext.current = new ExecutionContext(GLOBAL_CODE);
         let names = Object.getOwnPropertyNames(global);
         for (let i = 0, n = names.length; i < n; i++) {
             delete global[names[i]];
         }
-        for (let key in globalScope) {
-            delete globalScope[key];
-        }
         moduleInstances = new WeakMap();
         globalStaticEnv = new StaticEnv();
 
@@ -254,7 +222,6 @@ Narcissus.interpreter = (function() {
         for (let key in globalBase) {
             let val = globalBase[key];
             global[key] = val;
-            globalScope[key] = val;
             // NB: this assumes globalBase never contains module or import bindings
             globalStaticEnv.bind(key, new Def());
         }
@@ -293,7 +260,6 @@ Narcissus.interpreter = (function() {
         functionInstance: null,
         result: undefined,
         target: null,
-        ecma3OnlyMode: false,
 
         // Execute a node in this execution context.
         execute: function(n) {
@@ -419,7 +385,7 @@ Narcissus.interpreter = (function() {
     function executeModule(n, x) {
         var m = x.scope.object[n.name];
         var inst = moduleInstances.get(m);
-        var x2 = new ExecutionContext(MODULE_CODE, x.version);
+        var x2 = new ExecutionContext(MODULE_CODE, true);
         x2.scope = inst.scope;
         x2.thisObject = m;
         x2.thisModule = m;
@@ -594,10 +560,7 @@ Narcissus.interpreter = (function() {
             s = execute(n.object, x);
             v = getValue(s);
 
-            // ECMA deviation to track extant browser JS implementation behavior.
-            t = ((v === null || v === undefined) && !x.ecma3OnlyMode)
-                ? v
-                : toObject(v, s, n.object);
+            t = (v === null || v === undefined) ? v : toObject(v, s, n.object);
             a = [];
             for (i in t)
                 a.push(i);
@@ -1218,7 +1181,7 @@ Narcissus.interpreter = (function() {
 
     var FIp = FunctionInternals.prototype = {
         call: function(f, t, a, x) {
-            var x2 = new ExecutionContext(FUNCTION_CODE, x.version);
+            var x2 = new ExecutionContext(FUNCTION_CODE, this.node.body.strict);
             x2.thisObject = t || global;
             x2.thisModule = null;
             x2.functionInstance = this;
@@ -1275,11 +1238,11 @@ Narcissus.interpreter = (function() {
         if (typeof s !== "string")
             return s;
 
-        var x = new ExecutionContext(GLOBAL_CODE, Narcissus.options.version);
+        var x = new ExecutionContext(GLOBAL_CODE);
         var ast = parser.parse(s, f, l);
         if (Narcissus.options.desugarExtensions)
             ast = desugaring.desugar(ast);
-        if (x.version === "harmony") {
+        if (ast.hasModules) {
             resolveGlobal(ast);
             instantiateModules(ast, x.scope);
         }
@@ -1364,7 +1327,7 @@ Narcissus.interpreter = (function() {
             return false;
         }
 
-        var x = new ExecutionContext(GLOBAL_CODE, Narcissus.options.version);
+        var x = new ExecutionContext(GLOBAL_CODE);
 
         // Line number in/out parameter to parser.parseStdin.
         var ln = {value: 0};
diff --git a/lib/jsparse.js b/lib/jsparse.js
index ff6a629..a45c788 100644
--- a/lib/jsparse.js
+++ b/lib/jsparse.js
@@ -82,8 +82,7 @@ Narcissus.parser = (function() {
         this.t = tokenizer;
         this.x = null;
         this.unexpectedEOF = false;
-        Narcissus.options.ecma3OnlyMode && (this.ecma3OnlyMode = true);
-        Narcissus.options.version === 185 && (this.mozillaMode = true);
+        Narcissus.options.mozillaMode && (this.mozillaMode = true);
         Narcissus.options.parenFreeMode && (this.parenFreeMode = true);
     }
 
@@ -162,8 +161,6 @@ Narcissus.parser = (function() {
 
     var Pp = Parser.prototype;
 
-    Pp.ecma3OnlyMode = false;
-
     Pp.mozillaMode = false;
 
     Pp.parenFreeMode = false;
@@ -214,9 +211,8 @@ Narcissus.parser = (function() {
         var node = this.newNode(scriptInit());
         var x2 = new StaticContext(node, node, inModule, inFunction);
         this.withContext(x2, function() {
-            this.Statements(node, false);
+            this.Statements(node, true);
         });
-        for (var i = 0, n = node.children.length; i < n && Pragma(node.children[i]); i++);
         if (expectEnd && !this.done())
             this.fail("expected end of input");
         return node;
@@ -431,14 +427,23 @@ Narcissus.parser = (function() {
     }
 
     /*
-     * Statements :: (node) -> void
+     * Statements :: (node[, boolean]) -> void
      *
      * Parses a sequence of Statements.
      */
-    Pp.Statements = function Statements(n) {
+    Pp.Statements = function Statements(n, topLevel) {
+        var prologue = !!topLevel;
         try {
-            while (!this.done() && this.peek(true) !== RIGHT_CURLY)
-                n.push(this.Statement());
+            while (!this.done() && this.peek(true) !== RIGHT_CURLY) {
+                var n2 = this.Statement();
+                n.push(n2);
+                if (prologue && Pragma(n2)) {
+                    this.x.strictMode = true;
+                    n.strict = true;
+                } else {
+                    prologue = false;
+                }
+            }
         } catch (e) {
             if (this.done())
                 this.unexpectedEOF = true;
@@ -453,7 +458,7 @@ Narcissus.parser = (function() {
         this.withContext(x2, function() {
             this.Statements(n);
         });
-        t.mustMatch(RIGHT_CURLY);
+        this.mustMatch(RIGHT_CURLY);
         return n;
     }
 
@@ -647,7 +652,7 @@ Narcissus.parser = (function() {
                     }
                     this.mustMatch(COLON);
                     n2.statements = this.newNode(blockInit());
-                    while ((tt=t.peek(true)) !== CASE && tt !== DEFAULT &&
+                    while ((tt=this.peek(true)) !== CASE && tt !== DEFAULT &&
                            tt !== RIGHT_CURLY)
                         n2.statements.push(this.Statement());
                     n.cases.push(n2);
@@ -761,16 +766,13 @@ Narcissus.parser = (function() {
             this.withContext(x2, function() {
                 n.body = this.Statement();
             });
-            t.mustMatch(WHILE);
+            this.mustMatch(WHILE);
             n.condition = this.HeadExpression();
-            if (!this.ecma3OnlyMode) {
-                // <script language="JavaScript"> (without version hints) may need
-                // automatic semicolon insertion without a newline after do-while.
-                // See http://bugzilla.mozilla.org/show_bug.cgi?id=238945.
-                this.match(SEMICOLON);
-                return n;
-            }
-            break;
+            // <script language="JavaScript"> (without version hints) may need
+            // automatic semicolon insertion without a newline after do-while.
+            // See http://bugzilla.mozilla.org/show_bug.cgi?id=238945.
+            this.match(SEMICOLON);
+            return n;
 
           case BREAK:
           case CONTINUE:
@@ -824,7 +826,7 @@ Narcissus.parser = (function() {
                     break;
                 }
                 if (this.match(IF)) {
-                    if (this.ecma3OnlyMode)
+                    if (!this.mozillaMode)
                         this.fail("Illegal catch guard");
                     if (n.catchClauses.length && !n.catchClauses.top().guard)
                         this.fail("Guarded catch after unguarded");
@@ -871,7 +873,7 @@ Narcissus.parser = (function() {
             break;
 
           case LET:
-            if (t.peek() === LEFT_PAREN) {
+            if (this.peek() === LEFT_PAREN) {
                 n = this.LetBlock(true);
                 return n;
             }
@@ -1208,8 +1210,6 @@ Narcissus.parser = (function() {
             this.fail("missing function identifier");
 
         var inModule = this.x.inModule;
-        // var x0 = this.x;
-        // this.x = new StaticContext(null, null, inModule, true, this.x.strictMode);
         x2 = new StaticContext(null, null, inModule, true, this.x.strictMode);
         this.withContext(x2, function() {
             this.mustMatch(LEFT_PAREN);
@@ -1245,7 +1245,6 @@ Narcissus.parser = (function() {
                 f.body = this.Script(inModule, true);
             }
         });
-        // this.x = x0;
 
         if (tt === LEFT_CURLY)
             this.mustMatch(RIGHT_CURLY);
@@ -1274,7 +1273,7 @@ Narcissus.parser = (function() {
         var n1, n2;
         do {
             n1 = this.Identifier();
-            if (t.match(ASSIGN)) {
+            if (this.match(ASSIGN)) {
                 n2 = this.ModuleExpression();
                 n1.initializer = n2;
                 if (n2.type === STRING)
@@ -1460,7 +1459,7 @@ Narcissus.parser = (function() {
             n = this.newNode({ type: FOR_IN, isLoop: true });
             if (this.match(IDENTIFIER)) {
                 // But sometimes they're for each..in.
-                if (this.t.token.value === "each")
+                if (this.mozillaMode && this.t.token.value === "each")
                     n.isEach = true;
                 else
                     this.t.unget();
@@ -1923,8 +1922,6 @@ Narcissus.parser = (function() {
                     tt = this.t.get();
                     if ((this.t.token.value === "get" || this.t.token.value === "set") &&
                         this.peek() === IDENTIFIER) {
-                        if (this.ecma3OnlyMode)
-                            this.fail("Illegal property accessor");
                         n.push(this.FunctionDefinition(true, EXPRESSED_FORM));
                     } else {
                         var comments = this.t.blockComments;
@@ -1933,8 +1930,6 @@ Narcissus.parser = (function() {
                             id = this.newNode({ type: IDENTIFIER });
                             break;
                           case RIGHT_CURLY:
-                            if (this.ecma3OnlyMode)
-                                this.fail("Illegal trailing ,");
                             break object_init;
                           default:
                             if (this.t.token.value in definitions.keywords) {
diff --git a/njs b/njs
index 6f0f748..e4b927c 100755
--- a/njs
+++ b/njs
@@ -44,12 +44,10 @@ if __name__ == '__main__':
             help='load Narcissus but run interactive SpiderMonkey shell')
     op.add_option('-E', '--expression-meta', dest='js_exps_meta', action='append',
             help='expression to evaluate with SpiderMonkey after loading Narcissus')
-    op.add_option('-H', '--harmony', dest='js_harmony', action='store_true',
-            help='enable ECMAScript Harmony mode')
     op.add_option('-P', '--parse-only', dest='js_parseonly', action='store_true',
             help='stop after the parsing stage and output pretty-printed source code')
-    op.add_option('-3', '--ecma3-only', dest='js_ecma3only', action='store_true',
-            help='restrict source language to ECMA-262 Edition 3')
+    op.add_option('-w', '--web-compatible', dest='js_webcompatible', action='store_true',
+            help='disable non-standard Mozilla extensions')
     op.add_option('-p', '--paren-free', dest='js_parenfree', action='store_true',
             help='use experimental paren-free syntax')
     op.add_option('-d', '--desugar', dest='js_desugar', action='store_true',
@@ -59,11 +57,8 @@ if __name__ == '__main__':
 
     cmd = ""
 
-    if options.js_harmony:
-        cmd += 'Narcissus.options.version = "harmony"; '
-
-    if options.js_ecma3only:
-        cmd += 'Narcissus.options.ecma3OnlyMode = true; '
+    if options.js_webcompatible:
+        cmd += 'Narcissus.options.mozillaMode = false; '
 
     if options.js_parenfree:
         cmd += 'Narcissus.options.parenFreeMode = true; '