Are there any open-source Esri map viewer equivalents that you recommend?

[alphayash]

I’m Working as an intern for a non-profit that has a need to present their geospatial data on their website. https://vidmateapp.win

I frequently see websites with a data viewer that looks to be hosted in Esri Mapviewer. I think I could possibly learn the tool, but given I work at a non-profit which is on a tight budget, I’m curious what kind (if any) free/open-source tools exist out there that are worth investing your time in.

[Anonymous User]

One of the most common FOSS web mapping tools is Leaflet.

If JavaScript isn't your jam, there is a Python templating engine for Leaflet called Folium.

ESRI also has a series of Leaflet plugins you can find here.