The Functional Agent-Based language for Simulations (FABLES) is a programming language and its integrated environment developed by AITIA specially designed for creating agent-based simulations. It requires minimal programming skills, as its formalism is similar to the mathematical formalism used in publications in the subject.

FABLES has a whole range of functions intended to make the use of the language easier like the language assistant, syntax highlighting, bracket matching and the context sensitive help. An observation wizard is also provided with the language, which gives great ease to creating visualizations from the simulations. With the above-described IDE this constitutes what is called Integrated Modeling Environment.