Checkstyle's repositories
checkstyle
Checkstyle is a development tool to help programmers write Java code that adheres to a coding standard. By default it supports the Google Java Style Guide and Sun Code Conventions, but is highly configurable. It can be invoked with an ANT task and a command line program.
sonar-checkstyle
Support on Checkstyle in SonarQube. Officially transfered from https://github.com/SonarQubeCommunity/sonar-checkstyle
eclipse-cs
The Eclipse Checkstyle plug-in integrates the Checkstyle Java code auditor into the Eclipse IDE. The plug-in provides real-time feedback to the user about violations of rules that check for coding style and possible error prone code constructs.
contribution
some useful sources that should not stay in main repo but it is good to host them
checkstyle.github.io
http://checkstyle.org
patch-filters
Suppression Filter for Checkstyle that is based on patch file