A simple Python script that renders a URL in a simple window using PySide/Qt.

browser.py

#!/usr/bin/env python

import sys, os
import argparse
from PySide.QtCore import *
from PySide.QtGui import *
from PySide.QtWebKit import *

class ValidateURL(argparse.Action):
    def __call__(self, parser, args, values, option_string=None):
        url = QUrl(values)
        if not url.isValid():
            raise argparse.ArgumentError(self, 'invalid')
        if url.scheme() == '':
            if not os.path.exists(url.toLocalFile()):
                raise argparse.ArgumentError(self, 'local file does not exist')
        elif url.scheme() != 'http' and url.scheme() != 'https' and url.scheme() != 'file':
            raise argparse.ArgumentError(self, 'unsupported url scheme')
        setattr(args, self.dest, url)

parser = argparse.ArgumentParser()
parser.add_argument("URL", help="The URL to render.", action=ValidateURL)
parser.add_argument("-F", "--fullscreen", action="store_true",
                    help="Render URL using the fullscreen.")
args = parser.parse_args()

app = QApplication(sys.argv)
desktop = app.desktop()
screenRect = desktop.screenGeometry(desktop.primaryScreen())
windowRect = QRect(0, 0, 800, 600)
if screenRect.width() < 800:
    windowRect.setWidth(screenRect.width())
if screenRect.height() < 600:
    windowRect.setHeight(screenRect.height())
windowRect.moveCenter(screenRect.center())
web = QWebView()
web.setGeometry(windowRect)
web.load(args.URL)
if args.fullscreen:
    web.setWindowFlags(Qt.FramelessWindowHint | Qt.WindowStaysOnTopHint)
    web.showFullScreen()
else:
    web.show()
web.raise_()
sys.exit(app.exec_())