TurboGears is a Python web application framework consisting of several WSGI components such as WebOb, SQLAlchemy, Genshi 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 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.
Versions before 2.3 would also use:
Templating languages other than Genshi can be used through the user's app's configuration file. Plugins currently supported in 2.1 are Myghty, Jinja2, Mako, Cheetah, and Kajiki. Kid support is not currently planned as Genshi is virtually identical. This list may continue to change in future versions.
TurboGears was originally created in 2005 by Kevin Dangoor as the framework behind the as yet unreleased Zesty News product. When he released it as an open source framework in the end of September 2005, it received more than 30,000 screencast downloads in the first 3 months.
January 2007 Kevin Dangoor retired as project leader and Alberto Valverde managed the project as his successor, but subsequently stepped down due to other personal commitments. Alberto is still involved in the TurboGears community through his ToscaWidgets project. The TurboGears project is now managed jointly by a group of about half a dozen core developers under the leadership of Mark Ramm (as the TurboGears 2 development lead) and Florent Aide (as the Turbogears 1.x release manager).
In June 2007 the community began experiments to put the TurboGears API on top of components and protocols used in Pylons and there was speculation that the two frameworks may finally be merging. However, the official TurboGears 2 documentation states that this is unlikely to happen, due to the "different, but compatible priorities" of both projects. Pylons wanted to stay focused on low level, extensible design while TurboGears was focused on offering a complete, user-friendly package, and so the two work together much in the same way Debian and Ubuntu do now. The new 2.x branch had its first stable release in May 2009.
As of Fall 2008, TurboGears has a large and healthy community with over 3000 users on the TurboGears mailing list, a book from Prentice Hall published in Nov. '06, and a number of open-source and proprietary TurboGears applications deployed to the real world. The development progresses at a moderate but steady pace and was also newly fueled by a successful participation of the project as a Google Summer of Code mentoring organization in 2008 and 2009. TurboGears 1.1, aimed at helping legacy sites make the transition to 2.x, was released in October 2009. A new revision of the book is in the works to update it in line with the changes TurboGears 2 has brought.
In 2010, the project faltered somewhat. The lead developers were called away due to real life issues. By the end of Jan, 2011, though, the project had begun reorganizing and working on getting back on track. After several months getting infrastructure in order and working through coding issues, TurboGears has managed to release new versions (2.0.4 and 2.1.2).
In 2013, while maintaining backward compatibility, the project has moved away from the Pylons codebase to support Python 3, provide speed ups and an easier install process. This led to the release of version 2.3.0 in August 2013. It has also been announced a faster release cycle which should lead to a maintenance release every ~3 months.
TurboGears development is now focused primarily on the new 2.x branch, with version 2.3 now being the main track with Python 3 support.
A transition path from the 1.x branch to the 2.x branch is provided through the 1.1 and 1.5 releases which moved the default ORM and templating languages to match the one used by the 2.x series. The TurboGears team made it clear to new users that 2.x is the future, and 1.x is merely maintained for the convenience of existing users.
During 2011 the lead developers of TurboGears have been in talks with the Pylons project to join forces with them and Repoze.BFG's developers as a new unified project called Pyramid. Due to the backward compatibility issues this move would have, and guaranteed TurboGears keeps being a reliable platform on long term, the current team decided to collaborate with the Pylons Project on everything possible but not to base the TurboGears core on Pyramid.
Future development, Python 3 support and speed improvements have happened in the 2.3 branch which has seen a full rewrite of the TurboGears core while keeping it backward compatible with existing applications, since that release TurboGears had its own core instead of being based on the Pylons framework.
During the 2.3 series the framework has been experimenting with a so-called "minimal mode" which makes it able to act as a micro-framework de facto reducing the dependencies from tens to just 3 and positioning TurboGears between Flask and Django in the rose of python frameworks for its objectives, as it aims as being able to scale from a micro-framework to a full-stack framework depending just on the fact that the TurboGears2 or the tg.devtools package is used.