All organizations · GSoC 2026 · Programming languages, Development tools

checkstyle

Helps to adheres of Java coding standard

Checkstyle is a development tool to help programmers write Java code that is easy to read and adheres to a coding standard. Our utility automates the process of checking Java code to spare humans of this boring (but important) task. This makes it ideal for projects that want to enforce a coding standard. Each and every check also forces our users who are not familiar with these standards to read them and makes them think about why these standards exist.

java
antlr
artificial-intelligence

static code analysis‎
code review tool
coding standards
coding conventions
artificial-intelligence

Project ideas

14 ideas on its 2026 ideas page. Sizes: 2 medium, 12 large. 11 mentors named.

Project Name: Implementation of auto-fix Recipes large
Project Name: Java 25 Language Features Support large
Project Name: Enhancement For Website medium
Project Name: AI-Powered XPath Generator for Checkstyle Suppressions large
Project Name: Markdown Javadoc Support large
Project Name: Optimization of distance between methods in single Java class large
Project Name: Reconcile formatters of Eclipse , NetBeans and IntelliJ IDEA IDEs by Checkstyle config large
Project Name: Open JDK Code convention coverage large
Project Name: Coverage of Documentation Comments Style Guide large
Project Name: Spellcheck of Identifiers by English dictionary large
Project Name: Eliminate Maven Plugin Usage medium
Project Name: Patch Suppression improvement large
Project Name: Extend Checker Framework Integration large
Project Name: Improve Google Style coverage on false negatives large

Read the ideas page. Ideas are for scope reference; never copy one into a proposal.

History

In GSoC since 2017, 8 years. Projects per year: '17: 5, '20: 3, '21: 2, '22: 1, '23: 2, '24: 3, '25: 5, '26: 6.

On GitHub

11 repositories pushed to in the last year. Main languages: Java (8), HTML (2).

Links and channels

Website: https://checkstyle.org
Ideas page: https://github.com/checkstyle/checkstyle/wiki/Checkstyle-GSoC-2026-Project-Ideas
Contributor guide: https://github.com/checkstyle/checkstyle/blob/master/.github/GSOC.md
Source code: https://github.com/checkstyle
Chat: https://discord.gg/FsUsYC2ura
Mailing list: https://groups.google.com/g/checkstyle-devel

go deeper in your terminal

git-into-gsoc org "checkstyle" --shortlist
git-into-gsoc repos "checkstyle"
git-into-gsoc issues --org "checkstyle"

or ask your assistant:
"Which checkstyle repositories merge
newcomers' pull requests, and which beginner
issues are still free?"

Those commands read live data: which repositories merge outside pull requests, and which beginner issues nobody has claimed. Install in two minutes.