Simian Similarity Analyzer

What Simian Similarity Analyzer is

Simian Similarity Analyzer scans files in a repository to find and report duplicated blocks of code. It runs on the Java Virtual Machine, and its generated JAR runs on JDK 8 or newer. The analyzer works with human-readable files, including source code, markup, stylesheets, Markdown, and plain text. Listed languages include Java, C, C++, C#, COBOL, Python, Ruby, PHP, JavaScript, TypeScript, HTML, XML, CSS, Sass, Less, Visual Basic, and Groovy. You can run it locally, from scripts, or in a build pipeline; the repository also documents a Gradle task for scanning project source files. Results are plain text by default, with XML, YAML, and editor-friendly formats available. Options let you set a duplicate-line threshold, include or exclude files, select languages, and ignore differences such as identifiers, strings, or numbers. The maker reports a JDK test that analyzed over 2.4 million lines and found more than 140,000 duplicate lines in under five seconds, with results varying by hardware, operating system, and options. Simian is open source under Apache Software License, Version 2.0. Quandary Peak Research, a Los Angeles-based consulting group, makes it, directs users to Stack Overflow for help, and welcomes GitHub contributions.

Who it suits

Simian suits developers and teams who want to locate repeated text in source files across a repository, including as part of scripts or a build pipeline. It is also suitable for users who can run software on the Java Virtual Machine and want an open-source analyzer with configurable scan and output options.

Limits

Simian is free and open source under Apache Software License, Version 2.0. Its generated JAR runs on JDK 8 or newer; the reported scan performance varies by hardware, operating system, and options.

Getting started

1. Visit https://simian.quandarypeak.com/.
2. Use a system with the Java Virtual Machine; the generated JAR runs on JDK 8 or newer.
3. Run Simian locally, from a script, or as part of a build pipeline.
4. Configure the duplicate-line threshold, file patterns, and language selection as needed.
5. For Gradle projects, follow the repository's documented integration example.

Verdict

Choose Simian if you need an open-source, configurable duplicate-code scanner that can run locally or in a build pipeline. It requires a Java runtime, and users seeking IDE integration should consider that the listed integration options do not include one.