computingframework that provides enterprise-level tools for use in python scripts and allows sites to leverage the capacity of google' web infrastructureand turbo gears--an integrated collection of tools including javascript librarya template systemcherrypy for web interactionand sqlobject for accessing databases using python' class model also in the framework category are zope--an open source web application server and toolkitwritten in and customizable with pythonin which websites are implemented using fundamentally object-oriented modelplone-- zope-based website builder which provides workflow model (called content management systemthat allows content producers to add their content to siteand other popular systems for website constructionincluding pylonsweb pycherrypyand webware many of these frameworks are based upon the now widespread mvc (model-viewcontrollerstructureand most provide state retention solutions that wrap database storage some make use of the orm (object relational mappingmodel we'll meet in the next part of the bookwhich superimposes python' classes onto relational database tablesand zope stores objects in your site in the zodb object-oriented database we'll study in the next part as well rich internet applications (revisiteddiscussed at the start of newer and emerging "rich internet application(riasystems such as flexsilverlightjavafxand pyjamas allow user interfaces implemented in web browsers to be much more dynamic and functional than html has traditionally allowed these are client-side solutionsbased generally upon ajax and javascriptwhich provide widget sets that rival those of traditional "desktopguis and provide for asynchronous communication with web servers according to some observerssuch interactivity is major component of the "web model ultimatelythe web browser is "desktopgui applicationtooalbeit one which is very widely available and which can be generalized with ria techniques to serve as platform for rendering other guisusing software layers that do not rely on particular gui library in effectrias turn web browsers into extendable guis at least that' their goal today compared to traditional guisrias gain some portability and deployment simplicityin exchange for decreased performance and increased software stack complexity moreovermuch as in the gui realmthere are already competing ria toolkits today which may add dependencies and impact portability unless pervasive frontrunner appearsusing ria application may require an install stepnot unlike desktop applications stay tunedthoughlike the web at largethe ria story is still work in progress the emerging html standardfor instancewhile likely not to become prevalent for some years to comemay obviate the need for ria browser plug-ins eventually network scripting