Neverlang and FeatureIDE just married

Language development is inherently complex. With the support of a suitable language development environment most computer scientists could develop their own domain-specific language (DSL) with relative ease. Yet, when the DSL is the result of a configuration over a language product line (LPL)\u2014a special software product line (SPL) of compilers/interpreters and corresponding IDE services\u2014they fail to provide adequate support. An environment for LPL engineering should facilitate the underlying process involving three distinct roles: a language engineer developing the LPL, a language deployer configuring a language product, and a language user using the language product. Neither IDEs nor SPLE environments can cater all three roles and fully support the LPL engineering process with distributed, incremental development, configuration, and deployment of language variants. In this paper, we present an LPL engineer ing process for the distributed, incremental development of LPLs and an integrated language product line development environment supporting this process, catering the three roles, and ensuring the consistency among all artifacts of the LPL: language components implementing a language feature, the feature model, language configurations and the resulting language products. To create such an environment, we married the Neverlang language workbench and AiDE its LPL engineering environment with the FeatureIDE SPL en gineering environment. While Neverlang supports the development of LPLs and deployment of language products, AiDE generates the feature model for the LPL under development, whereas FeatureIDE handles the feature configuration. We illustrate the applicability of the LPL engineering process and the suitability of our development environment for the three roles by showcasing its application for teaching programming with a growable language. In there, an LPL for Javascript was developed/refactored, 15 increasingly complex language products were configured/updated and finally deployed