You are absolutely right, there are many options which we looked at before we began with the project. None of existing solutions provided the features we needed

You are absolutely right, there are many options which we looked at before we began with the project. None of existing solutions provided the features we needed: Authentication and authorization to meet our compliance needs, a satisfactory UI/UX, message streaming with JavaScript filters and a couple more features. We thought we can do better and just started hacking something. There's a lot more to come. I'll create a blog post describing in more detail why we've created Kowl.