diff --git a/src/calibre/__init__.py b/src/calibre/__init__.py
index 1456b62638..358a7ee4bf 100644
--- a/src/calibre/__init__.py
+++ b/src/calibre/__init__.py
@@ -320,6 +320,28 @@ def get_parsed_proxy(typ='http', debug=True):
                     prints('Using http proxy', str(ans))
                 return ans
 
+def get_proxy_info(proxy_scheme, proxy_string):
+    '''
+    Parse all proxy information from a proxy string (as returned by
+    get_proxies). The returned dict will have members set to None when the info
+    is not available in the string. If an exception occurs parsing the string
+    this method returns None.
+    '''
+    import urlparse
+    try:
+        proxy_url = u'%s://%s'%(proxy_scheme, proxy_string)
+        urlinfo = urlparse.urlparse(proxy_url)
+        ans = {
+            u'scheme': urlinfo.scheme,
+            u'hostname': urlinfo.hostname,
+            u'port': urlinfo.port,
+            u'username': urlinfo.username,
+            u'password': urlinfo.password,
+        }
+    except:
+        return None
+    return ans
+
 USER_AGENT = 'Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.13) Gecko/20101210 Gentoo Firefox/3.6.13'
 USER_AGENT_MOBILE = 'Mozilla/5.0 (Windows; U; Windows CE 5.1; rv:1.8.1a3) Gecko/20060610 Minimo/0.016'
 
diff --git a/src/calibre/constants.py b/src/calibre/constants.py
index 425dbdd9dd..9a429768b1 100644
--- a/src/calibre/constants.py
+++ b/src/calibre/constants.py
@@ -33,6 +33,7 @@ islinux   = not(iswindows or isosx or isbsd)
 isfrozen  = hasattr(sys, 'frozen')
 isunix = isosx or islinux
 isportable = os.environ.get('CALIBRE_PORTABLE_BUILD', None) is not None
+ispy3 = sys.version_info[0] > 2
 
 try:
     preferred_encoding = locale.getpreferredencoding()
diff --git a/src/calibre/gui2/__init__.py b/src/calibre/gui2/__init__.py
index 0e123bee8b..7d4a39fe4e 100644
--- a/src/calibre/gui2/__init__.py
+++ b/src/calibre/gui2/__init__.py
@@ -753,15 +753,24 @@ def open_local_file(path):
         url = QUrl.fromLocalFile(path)
         open_url(url)
 
-def is_ok_to_use_qt():
+def must_use_qt():
     global gui_thread, _store_app
     if (islinux or isbsd) and ':' not in os.environ.get('DISPLAY', ''):
-        return False
+        raise RuntimeError('X server required. If you are running on a'
+                ' headless machine, use xvfb')
     if _store_app is None and QApplication.instance() is None:
         _store_app = QApplication([])
     if gui_thread is None:
         gui_thread = QThread.currentThread()
-    return gui_thread is QThread.currentThread()
+    if gui_thread is not QThread.currentThread():
+        raise RuntimeError('Cannot use Qt in non GUI thread')
+
+def is_ok_to_use_qt():
+    try:
+        must_use_qt()
+    except RuntimeError:
+        return False
+    return True
 
 def is_gui_thread():
     global gui_thread
diff --git a/src/calibre/web/jsbrowser/__init__.py b/src/calibre/web/jsbrowser/__init__.py
new file mode 100644
index 0000000000..6e45b0e9e6
--- /dev/null
+++ b/src/calibre/web/jsbrowser/__init__.py
@@ -0,0 +1,10 @@
+#!/usr/bin/env python
+# vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import (unicode_literals, division, absolute_import,
+                        print_function)
+
+__license__   = 'GPL v3'
+__copyright__ = '2011, Kovid Goyal <kovid@kovidgoyal.net>'
+__docformat__ = 'restructuredtext en'
+
+
diff --git a/src/calibre/web/jsbrowser/browser.py b/src/calibre/web/jsbrowser/browser.py
new file mode 100644
index 0000000000..6a87594030
--- /dev/null
+++ b/src/calibre/web/jsbrowser/browser.py
@@ -0,0 +1,221 @@
+#!/usr/bin/env python
+# vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import (unicode_literals, division, absolute_import,
+                        print_function)
+
+__license__   = 'GPL v3'
+__copyright__ = '2011, Kovid Goyal <kovid@kovidgoyal.net>'
+__docformat__ = 'restructuredtext en'
+
+import os, pprint
+
+from PyQt4.Qt import (QObject, QNetworkAccessManager, QNetworkDiskCache,
+        QNetworkProxy, QNetworkProxyFactory)
+from PyQt4.QtWebKit import QWebPage
+
+from calibre import USER_AGENT, prints, get_proxies, get_proxy_info
+from calibre.constants import ispy3, config_dir
+from calibre.utils.logging import ThreadSafeLog
+from calibre.gui2 import must_use_qt
+
+class WebPage(QWebPage): # {{{
+
+    def __init__(self, log,
+            confirm_callback=None,
+            prompt_callback=None,
+            user_agent=USER_AGENT,
+            parent=None):
+        QWebPage.__init__(self, parent)
+
+        self.log = log
+        self.user_agent = user_agent if user_agent else USER_AGENT
+        self.confirm_callback = confirm_callback
+        self.prompt_callback = prompt_callback
+        self.setForwardUnsupportedContent(True)
+        self.unsupportedContent.connect(self.on_unsupported_content)
+
+    def userAgentForUrl(self, url):
+        return self.user_agent
+
+    def javaScriptAlert(self, frame, msg):
+        if self.view() is not None:
+            return QWebPage.javaScriptAlert(self, frame, msg)
+        prints('JSBrowser alert():', unicode(msg))
+
+    def javaScriptConfirm(self, frame, msg):
+        if self.view() is not None:
+            return QWebPage.javaScriptConfirm(self, frame, msg)
+        if self.confirm_callback is not None:
+            return self.confirm_callback(unicode(msg))
+        return True
+
+    def javaScriptConsoleMessage(self, msg, lineno, source_id):
+        prints('JSBrowser msg():%s:%s:'%(unicode(source_id), lineno), unicode(msg))
+
+    def javaScriptPrompt(self, frame, msg, default_value, *args):
+        if self.view() is not None:
+            return QWebPage.javaScriptPrompt(self, frame, msg, default_value,
+                    *args)
+        if self.prompt_callback is None:
+            return (False, default_value) if ispy3 else False
+        value = self.prompt_callback(unicode(msg), unicode(default_value))
+        ok = value is not None
+        if ispy3:
+            return ok, value
+        if ok:
+            result = args[0]
+            result.clear()
+            result.append(value)
+        return ok
+
+    def shouldInterruptJavaScript(self):
+        if self.view() is not None:
+            return QWebPage.shouldInterruptJavaScript(self)
+        return True
+
+    def on_unsupported_content(self, reply):
+        self.log.warn('Unsupported content, ignoring: %s'%reply.url())
+
+# }}}
+
+class ProxyFactory(QNetworkProxyFactory): # {{{
+
+    def __init__(self, log):
+        QNetworkProxyFactory.__init__(self)
+        proxies = get_proxies()
+        self.proxies = {}
+        for scheme, proxy_string in proxies.iteritems():
+            scheme = scheme.lower()
+            info = get_proxy_info(scheme, proxy_string)
+            if info is None: continue
+            hn, port = info['hostname'], info['port']
+            if not hn or not port: continue
+            log.debug('JSBrowser using proxy:', pprint.pformat(info))
+            pt = {'socks5':QNetworkProxy.Socks5Proxy}.get(scheme,
+                    QNetworkProxy.HttpProxy)
+            proxy = QNetworkProxy(pt, hn, port)
+            un, pw = info['username'], info['password']
+            if un:
+                proxy.setUser(un)
+            if pw:
+                proxy.setPassword(pw)
+            self.proxies[scheme] = proxy
+
+        self.default_proxy = QNetworkProxy(QNetworkProxy.DefaultProxy)
+
+    def queryProxy(self, query):
+        scheme = unicode(query.protocolTag()).lower()
+        return [self.proxies.get(scheme, self.default_proxy)]
+# }}}
+
+class NetworkAccessManager(QNetworkAccessManager): # {{{
+
+    OPERATION_NAMES = { getattr(QNetworkAccessManager, '%sOperation'%x) :
+            x.upper() for x in ('Head', 'Get', 'Put', 'Post', 'Delete',
+                'Custom')
+    }
+
+    def __init__(self, log, use_disk_cache=True, parent=None):
+        QNetworkAccessManager.__init__(self, parent)
+        self.log = log
+        if use_disk_cache:
+            self.cache = QNetworkDiskCache(self)
+            self.cache.setCacheDirectory(os.path.join(config_dir, 'caches',
+                'jsbrowser'))
+            self.setCache(self.cache)
+        self.sslErrors.connect(self.on_ssl_errors)
+        self.pf = ProxyFactory(log)
+        self.setProxyFactory(self.pf)
+        self.finished.connect(self.on_finished)
+
+    def on_ssl_errors(self, reply, errors):
+        reply.ignoreSslErrors()
+
+    def createRequest(self, operation, request, data):
+        url = unicode(request.url().toString())
+        operation_name = self.OPERATION_NAMES[operation]
+        debug = []
+        debug.append(('Request: %s %s' % (operation_name, url)))
+        for h in request.rawHeaderList():
+            try:
+                d = '  %s: %s' % (h, request.rawHeader(h))
+            except:
+                d = '  %r: %r' % (h, request.rawHeader(h))
+            debug.append(d)
+
+        if data is not None:
+            raw = data.peek(1024)
+            try:
+                raw = raw.decode('utf-8')
+            except:
+                raw = repr(raw)
+            debug.append('  Request data: %s'%raw)
+
+        self.log.debug('\n'.join(debug))
+        return QNetworkAccessManager.createRequest(self, operation, request,
+                data)
+
+    def on_finished(self, reply):
+        reply_url = unicode(reply.url().toString())
+
+        if reply.error():
+            self.log.warn("Reply error: %s - %d (%s)" %
+                (reply_url, reply.error(), reply.errorString()))
+        else:
+            debug = []
+            debug.append("Reply successful: %s" % reply_url)
+            for h in reply.rawHeaderList():
+                try:
+                    d = '  %s: %s' % (h, reply.rawHeader(h))
+                except:
+                    d = '  %r: %r' % (h, reply.rawHeader(h))
+                debug.append(d)
+            self.log.debug('\n'.join(debug))
+# }}}
+
+class Browser(QObject):
+
+    def __init__(self,
+            # Logging. If None, uses a default log, which does not output
+            # debugging info
+            log = None,
+            # Receives a string and returns True/False. By default, returns
+            # True for all strings
+            confirm_callback=None,
+
+            # Prompt callback. Receives a msg string and a default value
+            # string. Should return the user input value or None if the user
+            # canceled the prompt. By default returns None.
+            prompt_callback=None,
+
+            # User agent to be used
+            user_agent=USER_AGENT,
+
+            # If True a disk cache is used
+            use_disk_cache=True,
+
+            # Verbosity
+            verbosity = 0
+        ):
+        must_use_qt()
+        QObject.__init__(self)
+
+        if log is None:
+            log = ThreadSafeLog()
+        if verbosity:
+            log.filter_level = log.DEBUG
+
+        self.jquery_lib = P('content_server/jquery.js', data=True,
+                allow_user_override=False).decode('utf-8')
+        self.simulate_lib = P('jquery.simulate.js', data=True,
+                allow_user_override=False).decode('utf-8')
+
+        self.page = WebPage(log, confirm_callback=confirm_callback,
+                prompt_callback=prompt_callback, user_agent=user_agent,
+                parent=self)
+        self.nam = NetworkAccessManager(log, use_disk_cache=use_disk_cache, parent=self)
+        self.page.setNetworkAccessManager(self.nam)
+
+    def visit(self, url):
+        pass
+