Ask HN: What tools for collaboration do you use for study groups?

I'm starting a group for learning to code at my workplace, and an early hurdle we're reaching is being able to communicate outside of work. We use Slack at my workplace, but I don't think that'll be the best form of communication for this.

I was thinking either Google Groups or a phpBB forum, but neither of these are a perfect fit either. These may be the best option, but I was hoping others here have run into this before.

If you have any tips in general about starting a group like this, I'm completely open to those as well! Cheers!