FAQ

Is CFDL open source?

No. CFDL is licensed under the PolyForm Noncommercial License 1.0.0: free for any noncommercial purpose, and use by or for a business needs a commercial license. The source is not distributed. 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). Checked against references: every domain pack is gated by benchmark suites diffed against independent reference models, with 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 and questions are welcome at support@cfdl.dev.

How stable is the language?

Pre-1.0: the language and IR are at v0.1, and interfaces may change until 1.0 freezes the IR and Results schemas — additive-only after that. The Specification defines what the language is today, and every run records the engine version that produced it, so a result can always be traced to the behavior that made it.

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.