Domain-specific modeling (DSM) makes software more accessible and inclusive, leveraging the expertise and knowledge of various experts instead of relying solely on technical experts. However, the widespread adoption of DSM is hampered due to poor tool support and modeling languages. In recent years, projectional editing has proven to be a promising approach to creating and manipulating domain-specific languages. This editing approach contrasts with traditional parser-based editing by allowing user edits to directly modify the abstract syntax tree. It supports various notations, enabling more intuitive languages and facilitating language extension and composition. However, current projectional editing solutions are heavyweight, platform-specific, and hard to integrate with. We aim to provide better support for this paradigm and make modeling more accessible to domain experts. Thus, we present Gentleman, a lightweight web-based projectional editor. With Gentleman, users can create models with simple structures and manipulate them with user-friendly projections. We evaluate Gentleman through a user study, demonstrating its ability to create and manipulate models effectively.