The best open source alternative to Plottr is Manuskript. If that doesn't suit you, our users have ranked more than 50 alternatives to Plottr and ten of them is open source so hopefully you can find a suitable replacement. Other interesting open source alternatives to Plottr are novelWriter, bibisco, Fantasia Archive and Aevon.
Open-source software offering a hierarchical outliner, distraction-free editor, character management, plot tools, Snowflake method support, section multi-organization, customizable writing workflows, cross-platform availability, and export to standard formats.
novelWriter is a Markdown-like text editor designed for writing novels and larger projects of many smaller plain text documents. It uses its own flavor of Markdown that supports a meta data syntax for comments, synopsis and cross-referencing between files.
Desktop application for novel structuring, offering chapter and scene management, distraction-free text editing, detailed timeline, character interviews, multilingual support, export to publishing formats, revision history, relationship diagrams, and writing goal tracking.
Free offline worldbuilding and story creation tool with dozens of templates, complex tagging options, document linking, and project-wide search. Template examples: characters, places, events, religions, currencies, magic, species, languages.
Aevon is the all-in-one workspace where authors manage manuscripts, characters, maps, lore, and items — all connected and always in sync.
Free, open-source writing software that bridges the gap between outlining and drafting. Import your existing outline from Plottr, yWriter, or Obsidian and draft with your scene beats, character notes, and story structure visible alongside your prose.
Zavala is a modern take on a traditional outliner. It supports all the things you want in a Mac app like multiple windows, keyboard shortcuts, a customizable toolbar, and a full menu bar.
Fountain is inspired by Markdown syntax, intended as a simple markup syntax for writing, editing and sharing screenplays in plain, human-readable text.
Neverkin is a free and open-source webapp aimed at different kind of writers and storytellers that have large stories or worlds to keep track of. It includes a wide range of features and it keeps evolving. For example, Neverkin provides:
France
EU
Italy
United States
Canada
Ireland
It enables to visualise the plot the same way Plottr does.