Open Source

The roots of Placemark are in open source software. The product is built on open source foundations and the Placemark team has contributed open source projects to the ecosystem that have hundreds of thousands of users.
High-impact open source modules developed & maintained by the Placemark team
Code improvements & sponsorship for critical open source dependencies
Placemark itself

Placemark open source projects


A versatile converter that translates KML, TCX, and GPX formats to GeoJSON. Used by numerous other projects, this JavaScript/TypeScript module has been constantly improved since 2013.


An advanced converter module from GeoJSON to KML. tokml supports a wide range of GeoJSON inputs, and even can translate folder structures into the KML format.


Opening and saving files from a browser is complex, as we've written before. This module simplifies the process, working around tricky browser APIs and inconsistencies. Placemark uses flat-drop-files for its powerful file import methods.


check-geojson is a next-generation GeoJSON linter. Unlike other linting or validation utilities, it has both the ability to flag issues down to the specific line and character that caused an issue, but also a mode that allows partially-valid GeoJSON data to be parsed.


the polyline module converts to and from Google's encoded polyline standard and GeoJSON.


a niche but essential module that converts between centerpoint/zoom combinations and bounding boxes.

Placemark Figma plugin

create vector maps right in Figma, using open data, and use them however you'd like.

Sponsored & supported projects

Placemark is a minor financial supporter of open source projects at this stage.


Application framework


State management module


Data validation module
Code contributions