BrontoSource vs OpenRewrite

BrontoSource is a desktop tool for deterministic C++ refactoring across large repositories. Teams define explicit transformation rules and apply them across thousands of files. Documented operations include expression matching, extraction, and inlining for functions, constructors, type aliases, enumerators, namespaces, macros, declarations, types, and lambda captures. The command-line tool accepts Clang arguments, a compilation database, or compile_flags.txt, then can generate Fossil-format edits, merge edit files, and apply changes. BrontoSource describes its output as repeatable, traceable diffs for review. Its homepage reports 100M+ lines transformed safely and 10,000+ files refactored in one transformation. The product is in early access, with access arranged through BrontoSource; its API can also be tried on Compiler Explorer without installation. Pricing is on request. A header-only support library supports CMake 3.10.0+ and Bazel 8.1.1+ and uses 0BSD.

OpenRewrite is an open-source ecosystem for automated code refactoring, aimed at updating code and reducing technical debt. It represents code as Lossless Semantic Trees, applies transformations, and prints the result back into source code for review. Its recipes cover framework migrations, security fixes, and style consistency, and can be written in YAML, Refaster templates, or Java. Maven and Gradle plugins run recipes locally as part of builds, one repository at a time. The Maven plugin offers a dry run that reports potential changes and writes diff files; recipes run only when explicitly activated by name. Documented support includes Java, Kotlin, and Groovy, plus formats such as HCL, JSON, Properties, Protobuf, TOML, XML, and YAML. Framework coverage includes Spring, Quarkus, and Micronaut. The recipe index lists 4,183 recipes across modules. Core and language libraries use Apache License 2.0, but some recipes have other licensing terms. Core is free; some artifacts require authenticated repository access, and some recipes require a Moderne subscription.