Table of Contents

Working with the team

Generally it is sensible to check with the other developers if you are planning to make a change to NetSurf intended to be merged.

We are often about on the IRC channel but failing that the developer mailing list is a good place to try.

All the project sources are held in public git repositories

Compilation environment

Compiling a development edition of NetSurf requires a POSIX style environment. Typically this means a Linux based system although Free BSD, Open BSD, Mac OS X and Haiku all known to work.


Compilation for non POSIX toolkits/frontends (e.g. RISC OS) generally relies upon a cross compilation environment which is generated using the makefiles found in our toolchains repository. These toolchains are built by the Continuous Integration (CI) system and the results of the system are published as a convenience.

Quick setup

The quick start guide can be used to get a development environment setup quickly and uses the script the core team utilises.

Manual setup

The Manual environment setup and compilation method is covered by the details in the netsurf libraries document for the core libraries and then one of the building documents for the specific frontend.

These documents are sometimes not completely up to date and the script should be considered canonical.


The logging interface controls debug and error messages not output through the GUI.

Unit testing

NetSurf unit tests provide basic test coverage of many core parts of the browser code such as url parsing and utility functions.

Integration testing

The monkey frontend is used to perform complex tests involving operating the browser as a user might (opening windows, navigating to websites and rendering the contents etc.)

A test is written as a set of operations in a yaml file. A test can be run using the python script

$ ./test/ -m ./nsmonkey -t test/monkey-tests/start-stop.yaml

There are very few tests within the netsurf repository. The large majority of integration tests are held within the netsurf-test repository.

To allow more effective use of these tests additional infrastructure has been constructed to allow groupings of tests to be run. This is used extensively by the CI system to perform integration testing on every commit.

Each test is a member of a group and the tests within each group are run together. Groups are listed within division index files. To run the integration tests the monkey-see-monkey-do python script is used. It downloads the test plan for a division from the netsurf test infrastructrure and executes it.

$ ./test/monkey-see-monkey-do
Fetching tests...
Parsing tests...
Running tests...
Start group: initial
  [ Basic checks that the browser can start and stop ]
  => Run test: start-stop-no-js.yaml
  => Run test: basic-navigation.yaml
  => Run test: start-stop.yaml
Start group: no-networking
  [ Tests that require no networking ]
  => Run test: resource-scheme.yaml
Start group: ecmascript
  [ ECMAScript tests ]

Documented API

The NetSurf code makes use of Doxygen for code documentation.

There are several documents which detail specific aspects of the codebase and APIs.

Core window

The core window API allows frontends to use generic core code for user interface elements beyond the browser render.

Source object caching

The source object caching provides a way for downloaded content to be kept on a persistent storage medium such as hard disc to make future retrieval of that content quickly.


Javascript provision is split into four parts:


JavaScript is provided by integrating the duktape library. There are instructions on how to update the library.

Interface binding

In order for javascript programs to to interact with the page contents it must use the Document Object Model (DOM) and Cascading Style Sheet Object Model (CSSOM) API.

These interfaces are described using web Interface Description Language (IDL) within the relevant specifications (e.g.

Each interface described by the webIDL must be bound (connected) to the browsers internal representation for the DOM or CSS, etc. The process of writing bindings is ongoing.