Checkstyle vs markdownlint

Checkstyle is a free Java source-code analyzer for programmers who follow a coding standard. It checks naming, imports, Javadoc, formatting, class design, and coding practices against configurable rules. You can select supplied Google Java Style, Sun Conventions, OpenJDK Style, or Doc Style configurations, or create your own. Checkstyle runs from its command-line tool or as an Ant task, with documented Maven and Gradle integrations. Listed IDE and CI integrations include Eclipse, Bamboo, GitHub Actions, Codacy, and Code Climate. It runs on Linux, macOS, and Windows. The current site says it parses Java features through Java 25; versions 13.x and 14.x require Java runtime 21 or newer. Analysis is single-file and source-level, without expression-type determination or a full inheritance hierarchy. Releases are available through GitHub releases and Maven Central, including a standalone all-in-one JAR. It is licensed under LGPL-2.1-or-later and supports only the latest version.

markdownlint has no write-up on Specifiction yet; its figures are above.