Become familiar with source code

Sourcetrail, an interactive source code explorer, becomes open source

Sarah Schlothauer
© Shutterstock / Bakhtiar Zein (modified)

Another helpful tool becomes free and open source software. Coati Software’s Sourcetrail is an interactive source code explorer that helps developers understand what is going on in existing source code and provides helpful context. You can connect various editors to it with a plugin and all source code is private, as it runs locally on your machine.

Another celebration for FOSS. Sourcetrail, the cross-platform source explorer is now officially open source and free to use under the GNU General Public License. The project moved to an open source model instead of offering a paid commercial license. This model change will bring Sourcetrail to a wider consumer base, and more developers will be able to use it.

The Patreon for Coati Software offers several tiers for sponsors for those who wish to say thanks and see how its development will continue.

Changing to an open source model will not bring any major changes, according to the announcement blog by Eberhard Gräther.

Gräther writes about the change:

Looking at other companies in the field, it seemed that to make more money, our only option was making our licenses more and more expensive, which in turn would limit our audience to fewer developers. We always dismissed the idea because we started to make Sourcetrail to benefit as many developers as possible and not to be a premium product for a few people in a handful of companies.

Since the announcement, the GitHub repository saw 10k visitors, gained 1.8k stars, 400 clones, 67 forks, and 10 pull requests. Let’s see what all the hubbub is about and what Sourcetrail offers.

Sourcetrail: What does it accomplish?


User interface example. Source.

Sourcetrail is an interactive source explorer that helps developers navigate through unfamiliar source code. From its homepage:

Software developers spend most of their time figuring out existing source code, but common code editing tools offer little help for this task. Debuggers only allow detailed inspection of one narrow code path. ‘Find all references’ helps you in navigating between files, but doesn’t provide the context to see the big picture of all relevant dependencies. Sourcetrail provides both overview and details by combining an interactive dependency graph, a concise code view and efficient code search, all built into an easy-to-use cross-platform developer tool. It supports you in exploring legacy code, understanding the implementation and refactoring the software architecture, making it a fun experience for the whole family!

The UI consists of three different parts: search, graph, and code display.

Since Sourcetrail does not establish an internet connection, all confidential code is secure. All data will remain on your local machine.

Indexed data is saved in the .srctrldb file. When logging is enabled, some of the data logs in data/logs.

It supports Windows, macOS, and Linux operating systems.

Supported languages

Out of the box, Sourcetrail supports C and C++ (powered by Clang 8.0.1), Java 10 and lower, and includes beta support for Python 2 and Python 3.

However, you can also write custom language extensions with an SDK, SourcetrailDB. The SDK allows you to start a language packet using whichever programming language you choose. Building upon already existing frameworks and tools is a good idea for getting started.

SEE ALSO: Visual Studio Online offers remote access to development environments

Check out the language extension guide for some tips.

There is also an open issue for updating the Java indexer to at least the current LTS, Java 11. Can you help out?

Available code editors

Sourcetrail can partner up with a number of code editors via a plugin. This allows users to switch between browsing the source code and writing.

As of right now, supported editors include:

  • Atom
  • CLion
  • Eclipse
  • Emacs
  • IntelliJ IDEA
  • Vim
  • Visual Studio Code

SEE ALSO: Fund open source developers with GitHub Sponsors

Check it out

Follow the quick start guide and see what it can do. Sourcetrail offers a Project Setup Wizard for easy project creation and includes an introduction to the user interface.

The latest release is version 2019.4.61.

Requirements include Git and CMake v3.12. Windows users require Visual Studio; Unix users require ccache and a few required dependencies, as listed on GitHub.

Sarah Schlothauer

Sarah Schlothauer

All Posts by Sarah Schlothauer

Sarah Schlothauer is the editor for She received her Bachelor's degree from Monmouth University, West Long Branch, New Jersey. She currently lives in Frankfurt, Germany with her husband and cat where she enjoys reading, writing, and medieval reenactment. She is also the editor for Conditio Humana, an online magazine about ethics, AI, and technology.

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