#BeWelcome is GPL2 and written in PHP
https://github.com/BeWelcome/rox
#TrustRoots is MIT and looks to be in NodeJS
https://github.com/Trustroots/trustroots
#Couchers is also MIT and looks like they are going with Python, TypeScript and React
https://github.com/Couchers-org/couchers
:earth_africa: BeWelcome lets you share a place to stay, connect with travellers, meet up and find accommodation on your journey. It is and will always be a free, open source, non for profit, democ...
out of all 3, #Couchers seems to have taken the most effort to fully address the human/community safeguarding issues that plague any service like this (incidentally, I'm not sure if people realise that in many countries the moment they invite someone into their house they incur a formal legal duty of care to look after them and can incur legal penalties if things go wrong...)