Edit: Apparently there are 3 main software used by various regions across the world:

• https://demosphere.net/en
• https://gancio.org/instances
  • more here: https://fedidb.com/software/gancio
• https://lauti.org/#instances

In greece we have https://kinimatorama.net/ which is a calendar of upcoming mainly anarchist (but also generally leftist) events, like protests, squat bars, free cinema, mutal aid kitchens, live perfomances, festivals etc. and also allows you to filter by city, type of event etc.

I'm curious to know if there's anything similar to other countries. It has helped me really a lot to stay active in the movement and meet like-minded people (especially since I dont have instagram and also dont use fb to check for events).

Edit: I just found out that kinimatorama is based on a specific software that is also used by other countries. They list the countries here https://demosphere.net/en

Also thanks to poVoq and wakest, I learnt about 2 other software for similar uses: https://lauti.org/ and https://gancio.org/instances