I'm glad you brought Opa up. I saw it a while ago and thought it was interesting, until I saw the license it used (AGPL). Thankfully, your comment made me seek

I'm glad you brought Opa up. I saw it a while ago and thought it was interesting, until I saw the license it used (AGPL). Thankfully, your comment made me seek it out again and I saw they also added MIT for the framework part, so that apps can be licensed in any language. Will have to try it out now that they have given users that choice.