What is InRule?

InRule is a commercial business rules management system. Organisations use it to author, test, version, and execute decision logic outside their line-of-business applications. Rules are written in InRule's vocabulary and rule markup, then run through services such as irServer that .NET and other applications call at runtime.

The platform includes desktop and web authoring (irAuthor, Author Studio), verification (irVerify), and deployment into enterprise environments. Authors can work in natural-language style editors, decision tables, and expression builders. Versioning supports effective dates so different rule sets can apply at different points in time. InRule is commonly adopted in insurance, lending, benefits, and similar programmes on Microsoft-centric stacks, including integrations with Dynamics 365 and Power Platform.

InRule vs Lemma

Lemma is an open-source declarative language (Apache 2.0). Rules live in textual specifications that read like structured policy, with built-in temporal versioning and explainable evaluation. One file is the authoritative artifact for engineers, compliance, and the runtime.

InRule centres on a licensed BRMS, proprietary rule artifacts, and vendor-provided authoring and runtime. Lemma centres on a language you can own, diff in git, and embed without a rules-vendor subscription. Many teams compare them when choosing between an enterprise BRMS and an open rules language for governed, long-lived decision logic.

A complete, more comprehensive comparison is coming soon. In the meantime, if you are weighing InRule against Lemma for a specific programme, schedule a call with our founder Ben Rogmans to discuss when Lemma is the superior solution.