Trelby is a free, open-source screenwriting software designed to help writers create scripts for films and television. It offers a user-friendly interface that allows users to format their scripts according to industry standards easily. The software includes features like character management, scene organization, and a built-in spell checker, making it a valuable tool for both novice and experienced screenwriters. Originally developed in 2011, Trelby is available for multiple operating systems, including Windows and Linux. Its lightweight design ensures quick performance, and since it is open-source, users can modify the software to suit their specific needs. This flexibility has contributed to its popularity among independent filmmakers and writers.