In the semantically rich field of conceptual modeling, there is a need for open and user-friendly platforms for the development of modeling tools. This need arises from the constant change in both established modeling standards (e.g., BPMN, UML, ArchiMate) and domain-specific requirements. In application, such adaptations manifest themselves in the realization of enterprise information systems, which are constantly evolving in the face of technical challenges. This article is a translated version of the German article ADOxx: Eine Low-Code-Plattform für die Entwicklung von Modellierungswerkzeugen, which presents a conceptual low-code approach for open metamodeling platforms. The resulting approach is prototypically implemented on the basis of ADOxx. Low-code concepts such as visual drag-and-drop editors, point-and-click interactions, and the principle of reuse play a central role here. The latter enables the efficient integration of a wide variety of components from existing implementations, which have been compiled on the basis of over 50 modeling tools that have already been developed. The corresponding requirements for the approach presented are based on an evolutionary development process derived from the tools developed with different versions of the platform. Low-code metamodeling platforms require the intuitive realization of domain-specific modeling tools and the simultaneous establishment of new development processes in conceptual modeling. The realization of this claim is in line with current trends in the field of low-code development platforms, which are driven by the ongoing adaptation to advanced functionalities—such as the integration of external services and security mechanisms that were previously implemented primarily through traditional programming.