Apollo is a research project started by source{d} to find duplicated source code at scale. It is written in Python3 and relies on source{d} engine to process "big" source code.

Big source code warehouses like GitHub inevitably contain much duplication. Snippets, files or even projects may have very few differences. Apollo allows to accurately mine those groups of similar items. Subsequently, a report may be generated to point at refactoring possibilities. While Apollo can applied at small scale, e.g. within a single project, it does not try to replace any existing tools in that niche.

Behind the scenes, all source code samples are hashed with an algorithm which is Locality Sensitive Hashing-friendly: similar samples have similar, almost the same hashes. See the detailed explanation. The similarity is a subjective thing and depends on the human opinion. Apollo allows to combine various feature extractors and optimize their weights together with the overall threshold according to the reference dataset. The reference dataset is the only source of ground truth and should be manually labelled by a user, however, Apollo supplies the sane defaults.

Apollo is a research project aimed at maximum hackability, flexibility and rapid improvements. Gemini is its brother for the actual production usage. See more.