Arie van Deursen, Andy Zaidman, Maurício Aniche, Liam Clark, Gijs Weterings and Romi Kharisnawan.
Delft University of Technology, The Netherlands, July, 2018
We are proud to present the fourth edition of Delft Students on Software Architecture, a collection of 20 architectural descriptions of open source software systems written by students from Delft University of Technology during a master-level course that took place in the spring of 2018.
In this course, teams of approximately 4 students could adopt an open source project of choice on GitHub. The projects selected had to be sufficiently complex and actively maintained (one or more pull requests merged per day).
During an 8-week period, the students spent one third of their time on this course, and engaged with these systems in order to understand and describe their software architecture.
Inspired by Amy Brown and Greg Wilson's Architecture of Open Source Applications, we decided to organize each description as a chapter, resulting in the present online book.
The chapters share several common themes, which are based on smaller assignments the students conducted as part of the course. These themes cover different architectural 'theories' as available on the web or in textbooks. The course used Rozanski and Woods' Software Systems Architecture, and therefore several of their architectural viewpoints and perspectives recur.
The first theme is outward looking, focusing on the use of the system. Thus, many of the chapters contain an explicit stakeholder analysis, as well as a description of the context in which the systems operate. These were based on available online documentation, as well as on an analysis of open and recently closed (GitHub) issues for these systems.
A second theme involves the development viewpoint, covering modules, layers, components, and their inter-dependencies. Furthermore, it addresses integration and testing processes used for the system under analysis.
A third recurring theme is technical debt. Large and long existing projects are commonly vulnerable to debt. The students assessed the current debt in the systems and provided proposals on resolving this debt where possible.
Besides these common themes, students were encouraged to include an analysis of additional viewpoints and perspectives, addressing, e.g., security, privacy, regulatory, evolution, or product configuration aspects of the system they studied.
Last but not least, all students made a substantial effort to try to contribute to the actual projects. With these contributions the students had the ability to interact with the community; they often discussed with other developers and architects of the systems. This provided them insights in the architectural trade-offs made in these systems.
Student contributions included documentation changes, bug fixes, refactorings, as well as small new features. A list of contributions accepted by the projects under study is provided in the dedicated contributions chapter.
While we worked hard on the chapters to the best of our abilities, there might always be omissions and inaccuracies. We value your feedback on any of the material in the book. For your feedback, you can:
- Open an issue on our GitHub repository for this book.
- Offer an improvement to a chapter by posting a pull request on our GitHub repository.
- Contact @delftswa on Twitter.
- Send an email to Arie.vanDeursen at tudelft.nl.
We would like to thank:
- Our 2018, guest speakers, offering students an industrial perspective on software architecture: Bert Wolters, Sander Knape, Allard Buijze, and Bob Bijvoet.
- All open source developers who helpfully responded to the students' questions and contributions.
- The excellent gitbook toolset and gitbook hosting service making it easy to publish a collaborative book like this.
- Arie van Deursen, Maurício Aniche, Andy Zaidman, Valentine Mairet, Sander van den Oever (editors). Delft Students on Software Architecture: DESOSA 2017, 2017.
- Arie van Deursen, Maurício Aniche, Joop Aué (editors). Delft Students on Software Architecture: DESOSA 2016, 2016.
- Arie van Deursen and Rogier Slag (editors). Delft Students on Software Architecture: DESOSA 2015. DESOSA 2015, 2015.
- Arie van Deursen, Maurício Aniche, Joop Aué, Rogier Slag, Michael de Jong, Alex Nederlof, Eric Bouwers. A Collaborative Approach to Teach Software Architecture. 48th ACM Technical Symposium on Computer Science Education (SIGCSE), 2017.
- Arie van Deursen, Alex Nederlof, and Eric Bouwers. Teaching Software Architecture: with GitHub! avandeursen.com, December 2013.
- Amy Brown and Greg Wilson (editors). The Architecture of Open Source Applications. Volumes 1-2, 2012.
- Nick Rozanski and Eoin Woods. Software Systems Architecture: Working with Stakeholders Using Viewpoints and Perspectives. Addison-Wesley, 2012, 2nd edition.
The copyright of the chapters is with the authors of the chapters. All chapters are licensed under the Creative Commons Attribution 4.0 International License. Reuse of the material is permitted, provided adequate attribution (such as a link to the corresponding chapter on the DESOSA book site) is included.
Cover based on design by Valentine Mairet for DESOSA 2016. Image credits:
- Delft Nieuwe Kerk: Jan Arkesteijn at Wikimedia
- Cat: Smiling Cat Face With Open Mouth on Apple iOS 9.3 at Emojipedia
- Cat Paw: Designed by Freepik at Flaticon
