BrontoSource vs Comby
BrontoSource
brontosource.devComby
comby.devSide by side
| Figure | BrontoSource | Comby |
|---|---|---|
| Price from | — | — |
| Free plan | — | — |
| Free trial | — | — |
| Open source | — | — |
| Web | Yes | — |
| Windows | — | Yes |
| macOS | — | Yes |
| Linux | — | Yes |
| API | — | Yes |
| Self-hosted | — | Yes |
| Plans published | 0 | 0 |
| Spec score · Code Refactoring Tools | 7.7 (#11) | 7.7 (#12) |
| License | The support library uses the 0BSD license and compiles to nothing at runtime, according to the getting-started documentation. | The public comby-tools/comby GitHub repository identifies its license as Apache-2.0. |
| Purpose | Bronto is a tool for automatically performing smart find-and-replace across a codebase. | Comby is a tool for searching and changing code structure using lightweight templates. |
| Support | Users can contact [email protected] or create an issue on the public GitHub repository. | The help page directs users to the Gitter channel for usage questions and pattern-writing help, and to GitHub issues for installation problems. |
In their own words
BrontoSource
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.
Comby
Comby is a free, open-source tool for searching and changing code structure with lightweight templates. It recognizes basic syntax in code, strings, and comments across many languages, with parsers listed for C/C++, C#, Go, Java, JavaScript, Python, Rust, Swift, and TypeScript, plus a generic matcher for other formats. The project targets large refactors and one-off changes, and an interactive review mode lets users inspect proposed edits. Comby can run from its command line, Python bindings, or HTTP requests sent to a server on your machine. Installation instructions cover macOS with Homebrew, Ubuntu, Windows through Ubuntu on WSL, and Docker; building from source is also described. Linked projects include an Emacs package and a prototype VS Code extension. Other uses include structural code search, compiler fuzzing, test-case reduction, editor find and replace, and academic research. Comby matches balanced delimiters while accounting for comments and string literals, and supports regex search. It is self-hosted and available for API, Linux, macOS, and Windows use. The Apache-2.0 license is identified in the public repository.