Backstage

Backstage is an open-source framework for building developer portals, which aligns with the concept of a low-code/no-code platform for internal tools. It offers a centralized software catalog, software templates for quick project setup, and TechDocs for documentation, all of which contribute to streamlining internal development. While it doesn't explicitly market itself as 'low-code/no-code' in the same way Retool does, its emphasis on templates, plugins, and a unified developer experience suggests a similar goal of accelerating internal tool development. The platform supports integrations with various data sources and APIs through its plugin ecosystem, allows for code customization, and offers flexible deployment options. It also includes features like debugging, version control integration, audit logs, workflow automation (through its 'Workflows' plugin), and AI integration (via the 'AI Assistant - RAG AI' plugin). Custom theming is also supported.