Nelumbo was introduced at Declarative Amsterdam 2025: Nelumbo lets you define the syntax and semantics of your desired declarative language, and immediately edit, parse, test, and execute your language in any IDE and in the browser. The syntax is defined by type-declarations and language-patterns (similar to EBNF). The semantics is defined using first-order logic with natural support for 'not'.

The roots of Nelumbo lay in the desire to have the best tool for declarative language development, based on decades of experience building domain specific languages and language workbenches. Nelumbo is developed with integratibility in mind: Think of agentic AI, IDE’s, databases, WEB, etc.

The tutorial starts with an introduction and explanation of the Nelumbo language and semantics. However, the longest part of the session is about hands-on usage of Nelumbo. No installation is needed: only a computer with an internet connection.