FAQ

Is CFDL open source?

No — CFDL is source available under the Business Source License 1.1. You can read, modify, and use it in production; offering CFDL itself to third parties as a hosted or embedded commercial product requires a commercial license. Each released version converts to Apache 2.0 four years after release. Details: Licensing.

How is this different from spreadsheets and appraisal-grade DCF tools?

Three ways. Declarative and deterministic: a CFDL model is a text file that always produces the same IR and results — diffable, hashable, CI-testable. Natively stochastic: swap a constant for a distribution and the same model yields percentile bands around every metric, with seeded, reproducible draws (Stochastic Modeling). Parity is proven, not claimed: every domain pack is gated by benchmark suites diffed against independent Excel-grade references — schedule math held decimal-exact.

Will my results match Excel?

Schedule math uses decimal arithmetic with documented rounding (Excel's half-away-from-zero round()), and financial builtins are unit-tested against Excel-computed values. An excel_compat mode evaluates in IEEE-754 float64 to reproduce Excel's artifacts exactly where that matters.

Can I contribute?

External pull requests are not accepted — CFDL is maintained by a small internal team. Bug reports are welcome via GitHub issues.

How stable is the language?

Pre-1.0: the language/IR spec is v0.1 and interfaces may change until 1.0 freezes the IR and Results schemas (additive-only after that). The implementation status page tracks exactly what is implemented.

Which surface should I use?

Zero-install experiments → Playground. Files/git/CI → CLI. Notebooks and pandas → Python SDK. Service integration → API server. All embed the same engine and produce byte-identical results.