Google Summer of Code 2020

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Revision as of 11:36, 5 February 2020 by StefanoZacchiroli (talk | contribs) (Ideas list)
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General information

This page is the central point of information for Software Heritage participation into the Google Summer of Code program in 2020.

Google Summer of Code is a program where Google pays students stipends to work over the (northern hemisphere) summer on free software projects such as Software Heritage. Each student works with mentors from the community to complete a software project.

Accepted projects

I want to participate as a student

Great!, we are very glad for your interest in contributing to Software Heritage and we are looking forward to work together.


The following prerequisites apply to Software Heritage GSoC projects:

  • Python 3 is our language of choice, you should be fluent with that language to apply
  • Git is our version control system of choice, you should be familiar with it to apply
  • additional prerequisites depend on the project you will work on; check project descriptions for details

Before you apply

Here are the steps you should follow before applying, to make sure you have a good grasp of what we are doing at Software Heritage and how we do it:

  1. Follow our getting started guide: it will make sure you can locally run a (small) copy of the archive and ingest source code into it
  2. Create an account on our development forge
  3. Familiarize yourself with our code review workflow
  4. Make at least one simple change to any one of our software components and submit it as a diff for code review, following the above workflow. Easy hacks and Web UI issues are good options for what to fix, but feel free to submit any patch you think it might be useful.

What to include in your application

Make sure that your application includes the following information:

  • Describe the specific project you want to work on. What do you want to achieve? Why is it important? Why is it useful for Software Heritage? The project might be one of the project ideas that we have prepared below, or something else entirely that you want to contribute to Software Heritage. Your source code archival pet peeve, surprise us!
  • Detail your work plan: a brief description of how you plan to go about your project, including a list of deliverables and a timeline of when do you expect them to be available.
  • Include a reference to the diff you submitted before applying (see the "Before you apply" section above).

Ideas list

Below you can find a list of project ideas that are good options for a reasonably sized GSoC project. They are just suggestion though, don't feel obliged to pick one of them if there is nothing that fits your taste and abilities. Feel free to propose something else that you are excited about and that contributes to improve the Software Heritage archive: we will be happy to consider it!

Mine information from archived content

In addition to archival, Software Heritage indexes the retrieved source code artifacts, to enable semantic searches on the archive and scientific research.

Indexing can happen at the individual file-level (e.g., detect the programming language the file is written in or the license declared in its header), or at more coarse grained granularity (e.g., what metadata are declared for the most recently archived version of a given project).

A number of indexes are currently supported, such as:

  • file level mining:
    • MIME type detection (using libmagic)
    • license detection (using FOSSology/nomossa)
    • language detection (using Pygments)
    • ctags extraction (using universal-ctags)
  • project level mining:
    • Ruby gemspec metadata
    • Python PKG-INFO metadata
    • Maven pom.xml metadata
    • NPM package.json metadata

Writing additional indexers that extract more information from archived source code is welcome and would constitute a suitable GSoC project.

Name the kind of data mining you want to do!

For inspiration you can have a look at, as most package formats/package managers support dedicated ways of expressing metadata and we only support a small number of them up-to-now. But do not restrict your ambition to those, any kind of data extraction/mining you want to do on the archive could work.

You may also add support for multiple formats at once, using an external tool, such as Bolognese or bibliothecary.

Mine information from external sources

In addition to arching source code artifacts, Software Heritage is interested in archive metadata from external sources and correlate it to source code artifacts. This is also to enable semantic searches on the archive and scientific research.

Collecting this extrinsic metadata is a work in progress, and you are welcome to contribute to its implementation.

Improve and extend the archive Web UI

As you probably know already, The Software Heritage archive can be browsed on the Web. The code powering that interface is a Django application that also implements a Web API.

Several improvements are possible on the archive Web interface and would make great GSoC projects, some ideas to whet your appetite:

  • add new source code search criteria and improve the search interface
  • add developer-oriented features, e.g., source file history, blame/praise interface, in-browser edit (with patch download), ... (note that this will also require backend design and implementation)
  • improve accessibility
  • help us design and implement our next API version

Improve the Vault

The Software Heritage archive allows retrieval of archived objects of different formats. Once an object has been chosen for retrieval, it can be "cooked" using the Software Heritage Vault.

Right now the Vault has several limitations: it only handles two kinds of objects (revisions and directories), it requires recursively requesting the database to get the full subgraph of an object, and it generates revisions in an unpractical format (git fast-import).

Several improvements are possible:

  • add coverage for new kinds of objects (releases, snapshots and even origins?)
  • use our in-memory graph database swh-graph to speed up fetching the necessary subgraphs.
  • write cookers to output new formats (e.g git tarballs/git bundles or even other VCS?)
  • improve end-to-end testing
  • other general code improvements (better progress/error reporting in the frontend, etc.)

Internship topics

Independently from GSoC, we also maintain a separate list of academic Internships. They are usually offered to university students, but during GSoC they are also available as GSoC projects.

The currently available (GSoC) internship topics are:


GSoC students are encouraged to get in touch with the Software Heritage community using the standard development communication channels, and in particular our IRC channel (#swh-devel on FreeNode) and mailing list (swh-devel).

See our development information page for details.


See the official Google Summer of Code timeline.