History of Morepath

For more recent changes, see CHANGES.

Morepath was originally created by Martijn Faassen, but now has a team of developers (see CREDITS.txt in the project).

The genesis of Morepath is complex and involves a number of projects.

Web Framework Inspirations

Morepath was inspired by Zope, in particular its component architecture; a reimagined version of this is available in Reg, a core dependency of Morepath.

An additional inspiration was the Grok web framework Martijn conceived of and helped to create, which was based on Zope 3 technologies, and Pyramid, a reimagined version of Zope 3, created by Chris McDonough.

Pyramid in particular has been the source of a lot of ideas, including bits of implementation.

Once the core of Morepath had been created Martijn found there had been quite a bit of parallel evolution with Flask. Flask served as a later inspiration in its capabilities and documentation. Morepath also used Werkzeug (basis for Flask) for a while to implement its request and response objects, but eventually we found WebOb the better fit for Morepath and switched to that.

Configuration system

In 2006 Martijn co-founded the Grok web framework. The fundamental configuration mechanism this project uses was distilled into the Martian library:


Martian was reformulated by Chris McDonough (founder of the Pyramid project) into Venusian, a simpler, decorator based approach:


Morepath originally used Venusian as a foundation to its configuration system. It is good that Venusian defers execution of decorators until after import-time, but Venusian also makes setup more difficult to reason about for users than simply registering the decorator with the configuration system during import-time.

Morepath’s configuration system had grown over time and had grown a few hacks here and there. Removing Venusian was not simple as a result. The configuration system of Morepath was also underdocumented, a long standing issue in Morepath.

So in 2016 we extracted Morepath’s configuration system into its own reusable project, called dectate. Martijn also extensively refactored it and removed the Venusian dependency. Morepath now uses Dectate as a clean and well-documented configuration system.

Routing system

In 2009 Martijn wrote a library called Traject:


Martijn was familiar with Zope traversal. Zope traversal matches a URL with an object by parsing the URL and going through an object graph step by step to find the matching object. This works well for objects stored in an object database, as they’re already in such a graph. Martijn tried to make this work properly with a relational database exposed through an ORM, but noticed that he had to adjust the object mapping too much just to please the traversal system.

This led Martijn to a routing system, so expose the relational database objects to a URL. But he didn’t want to give up some nice properties of traversal, in particular that for any object that you can traverse to you can also generate a URL. He also wanted to maintain a separation between models and views. This led to the creation of Traject.

Martijn used Traject successfully in a number of projects (based on Grok), and also ported Traject to JavaScript as part of the Obviel client-side framework. While Traject is fairly web-framework independent, to Martijn’s knowledge Traject hasn’t found much adoption elsewhere.

Morepath contains a further evolution of the Traject concept (though not the Traject library directly).


In early 2010 Martijn started the iface project with Thomas Lotze. In 2012 Martijn started the Crom project. Finally he combined them into the Comparch project in 2013. He then renamed Comparch to Reg, and finally converted Reg to a generic function implementation.

In late 2014 there was another major change in Reg, when Martijn generalized it into a predicate dispatch implementation. In the summer of 2016 Stefano Taschini had a bunch of good ideas and we managed to simplify Reg’s implementation and got rid of its implicitness by introducing dispatch methods.

See Reg’s history section for more information on its history. The Reg project provides the fundamental registries that Morepath builds on.


In 2010 Martijn wrote a system called Dawnlight:


It was the core of an object publishing system with a system to find a model and a view for that model, based on a path. It used some concepts Martijn had learned while implementing Traject (a URL path can be seen as a stack that’s being consumed), and it was intended to be easy to plug in Traject. Martijn didn’t use Dawnlight himself, but it was adopted by the developers of the Cromlech web framework (Souheil Chelfouh and Alex Garel):


Morepath contains a reformulation of the Dawnlight system, particularly in its publisher module.

Combining it all

In 2013 Martijn started to work with CONTACT Software. They encouraged me to rethink these various topics. This led Martijn to combine these lines of development into Morepath: Reg registries, decorator-based configuration, and traject-style publication of models and resources.

Spinning a Web Framework

In the fall of 2013 Martijn gave a keynote speech at PyCon DE about the creative processes behind Morepath, called “Spinning a Web Framework”: