History of Morepath

For more recent changes, see CHANGES.

Morepath was written by Martijn Faassen (me writing this document).

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 I helped 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 I 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 I found WebOb the better fit for Morepath and switched to that.

Configuration system

In 2006 I 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. I like the way Venusian separates decorators from their execution, 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, plus I had a long-standing issue where I wanted to document the configuration system properly.

So in 2016 I extracted Morepath’s configuration system into its own reusable project, called dectate. I 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 I wrote a library called Traject:


I 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. I tried to make this work properly with a relational database exposed through an ORM, but noticed that I had to adjust the object mapping too much just to please the traversal system.

This led me to a routing system, so expose the relational database objects to a URL. But I 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. I also wanted to maintain a separation between models and views. This led to the creation of Traject.

I used Traject successfully in a number of projects (based on Grok). I also ported Traject to JavaScript as part of the Obviel client-side framework. While Traject is fairly web-framework independent, to my 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 I started the iface project with Thomas Lotze. In 2012 I started the Crom project. Finally I combined them into the Comparch project in 2013. I then renamed Comparch to Reg, and finally converted Reg to a generic function implementation.

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


In 2010 I 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 I’d 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. I didn’t use Dawnlight myself, 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 I started to work with CONTACT Software. They encouraged me to rethink these various topics. This led me to combine these lines of development into Morepath: Reg registries, decorator-based configuration using Venusian, and traject-style publication of models and resources.

Spinning a Web Framework

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