https://drakhanas.itch.io/cartulary
Cartulary is a one file, local only, free, open source worldbuilding tool that gives worldbuilders the freedom to chronicle their world; not their world as defined by constrained templates that only allow some fields and don't allow alteration of those fields. It has no installer, no account, no subscription, no cloud requirement, and no telemetry. It was coded via AI but contains no AI generation capabilities whatsoever, and the source is fully available. Just check the Cartulary_v1.1_Readable file, right click, and view it. 
It comes with 22 built in templates that cover the basics of most worldbuilding needs, but unlike the vast majority of world building resources, you can edit or delete any of these templates to fit your needs, or create entirely new templates designed by you and you alone.
Every template that comes built in and every template you make is treated the same by the app, meaning if you input a date range from the calendar - a calendar you can fully customize with your own months, days, and eras - that entry can now be linked to a map pin that will change based on the temporal year scrubbing in a map you've created, including pin label changes to track pinned entries names over time.
The entry will also show up in the Chronometric view, a graphical representation of anything that has temporal data. 
If you include family in your entry, there is also a built in family tree module called Linea that will render your characters family tree, and can even export as an md file with full Sosa-Stradonitz layout.
New in v1.1 is Stemma, a way to brainstorm ideas without having to leave the app, based on various mindmapping software. 
A member registered Nov 12, 2016 · View creator page →