RapidQL is an open-source project launched by RapidAPI that allows developers to query, combine, and aggregate data from multiple APIs and databases within a single API call, thereby simplifying the process of fetching data. By using a JSON-like query language implemented in JavaScript, RapidQL enables developers to perform simultaneous requests to APIs and databases, including MySQL, PostgreSQL, and MongoDB, while specifying only the necessary fields to avoid costly additional round trips. The project, which recently debuted on ProductHunt, supports over 10,000 public APIs available on RapidAPI's Marketplace. Developers are encouraged to try out RapidQL by creating example queries and sharing their projects, with the potential for their work to be highlighted by RapidAPI. As an open-source initiative, contributions to the codebase and development of integrations with additional data sources are welcomed.