Trelby is a free, open-source screenwriting software designed to provide a streamlined and efficient writing experience for screenwriters. It is available for both Windows and Linux operating systems. Trelby offers a range of features including a WYSIWYG editor, industry-standard formatting, and the ability to import and export scripts in various formats like PDF and Final Draft. It also includes tools for character name database management, scene location and character tracking, and reporting. Trelby aims to be an easy-to-use tool for both novice and experienced screenwriters, prioritizing simplicity and customization.