BrontoSource vs Moderne
BrontoSource
brontosource.devModerne
moderne.aiSide by side
| Figure | BrontoSource | Moderne |
|---|---|---|
| Price from | — | $2,000/mo |
| Free plan | — | — |
| Free trial | — | Yes |
| Open source | — | — |
| Web | Yes | Yes |
| Windows | — | Yes |
| macOS | — | Yes |
| Linux | — | Yes |
| API | — | Yes |
| Self-hosted | — | Yes |
| Plans published | 0 | 8 |
| Spec score · Code Refactoring Tools | 7.7 (#11) | 8.9 (#2) |
| Founded | BrontoSource says it was founded in September 2024 by a team of former Google engineers. | LinkedIn and Gartner list Moderne as founded in 2020. |
| Support | Users can contact [email protected] or create an issue on the public GitHub repository. | The contact page offers demo, sales, and quick-answer routing, while OpenRewrite is available as an open-source self-service starting point. |
Plans
Moderne
- Steering CommitteePriced on request
- Backpatch Alliance Member$2,000 a month
- Member$2,000 a month
- Backpatch Alliance Fully Managed ServicePriced on request
- Backpatch Alliance Steering CommitteePriced on request
- CommercialPriced on request
- EnterprisePriced on request
- Fully Managed ServicePriced on request
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.
Moderne
Moderne provides infrastructure for developers and AI coding agents to analyze, modernize, secure, and govern large software systems. Its hybrid SaaS runs deterministic recipes across thousands of repositories in a single-tenant cloud environment chosen by provider and region. Moderne DX instead runs within a customer network without outbound connectivity, keeping source code, recipes, and analysis inside that perimeter. Teams can group repositories by business unit and reporting structure using one CSV file, with results rolling up to leaders. DevCenter tracks upgrade, migration, and vulnerability status, including timelines and remaining occurrences. Its marketplace has thousands of type-aware recipes, and changesets support reviewing diffs, viewing results, and making multi-repository commits or pull requests. Changelog connects to source-control services and internal systems; agents can query change context through MCP and the GraphQL API. The product supports Linux, macOS, Windows, web, API, and self-hosted deployments. Pricing is paid, from $2,000/mo. Listed plans include Member at $2,000 a month, billed monthly or yearly; Commercial at a price agreed with the maker; Steering Committee at a price agreed with the maker; Enterprise at a price agreed with the maker; and Fully Managed Service at a price agreed with the maker. Moderne states it is SOC 2 Type 2 compliant.