Trustroots has a nice map-based interface, but lacks references and meetups. BeWelcome is my preferred option, and is open-source and has excellent financial transparency.
We're working on references :) I merged this PR yesterday https://github.com/Trustroots/trustroots/pull/1413, there is a bit more to work out for displaying them...
There is also a meetup feature already (see https://ideas.trustroots.org/2017/08/21/meeting-people-now-o...), it's a bit primitive right now, but it was a first iteration, and we've been discussing some next steps recently.
We are also open source! https://github.com/trustroots/ (with a node + react stack)
(most relevant, but dated, PR is https://github.com/Trustroots/trustroots/pull/1086)
(I also saw your comments on https://news.ycombinator.com/item?id=23219900)
This is a big deal actually. From what I've heard, One of the reasons why Hospitality Club fell into decline, was that the code-base was closed source and the original developer was reluctant to let go of it.
But really, I want to contribute to the original project, and given I am not the original developer, it still relies on the them (and any other founders) to open up contributions. Fortunately, in this case, they have :)