TurboGears is a Python web application framework consisting of several WSGI components such as WebOb, SQLAlchemy, Kajiki template language and Repoze. TurboGears is designed around the model–view–controller (MVC) architecture, much like Struts or Ruby on Rails, designed to make rapid web application development in Python easier and more maintainable. Since version 2.3 the framework has also been providing a "minimal mode" which enables it to act as a microframework for usage in environments where the whole stack is not required nor wanted. TurboGears components TurboGears is built on top of numerous disparate libraries and middleware. The default tools have changed between the 1.x, 2.x and 2.3+ series, but most of these components can be used in either as there is support for many alternative configurations. The following are the primary components a developer would interact with. TurboGears 2.x components SQLAlchemy (Model) - defines the table structures of the user's database and how to link them to Python objects the user's controller can interact with. Ming (Model) - provides the data access layer for MongoDB, much like SQLAlchemy defines how to link MongoDB collections to Python objects the user's controller can interact with. Kajiki (previously Genshi) (View) - defines templates for the HTML or XHTML the user will generate. This is where the user defines the front-end the client will interact with. Repoze - Repoze.who is used to handle security (identification and authentication). Users can define authorization rules based on predicates attached to controllers, the framework already provides some built-in predicates, but custom ones can be written. ToscaWidgets - is the primary widget library for creating forms and complex GUIs. Tosca by default will generate simple HTML forms, but can also be used as a middleware to connect to more advanced JavaScript widgets and toolkits. Unlike TurboGears 1.x, there is no longer a preferred/integrated JavaScript library. Gearbox - is the toolkit used by TurboGears to manage projects, create new ones and serve TurboGears applications but the user can also connect to Apache, Nginx, or any other WSGI-compatible webserver. Versions before 2.3 would also use: Pylons (Controller) - this middleware handles all the user's back-end logic and connects to the user's webserver to offer up data to the web. Paster was the command toolkit and webserver used in place of Gearbox. Repoze.what - Used to handle authorization respectively. When defining elements of the user's controller to be exposed to the web, repoze.what