The discovery feed is indeed pretty shit. You need to find your favorite hashtags / people to follow, like a bunch of things and then it starts getting better. Also you need to change the language in your settings. I'm German and also got a bunch of weird German politic topics despite I never reacted on any non-tech topics. After I removed German in my settings it got much better.
This is indeed a very biased comparision where some features in the comparision table are just claimed to be not supported by other (open source) solutions. Even after reaching out multiple times the article is not updated accordingly. So this has to be considered a sneaky marketing page to be honest.
I might be biased as I'm one of the Kowl authors but I can definetely tell that Lenses is affected negatively the most. Imo it is one of the most complete paid solutions and got the worst marks basically.
I'm curious what makes you look into other solutions than Kowl then? :). We are happy to add anything that is desired in the community. Now that Kafka connect support is also there we will most likely just expand the existing features (e.g. adding, editing schemas etc.).
Disclaimer: I'm one of the Kowl authors. I do not intend to hijack that post for Kowl content though!
Actually we haven't thought about message headers as we haven't used them for so long. Please submit an issue in GitHub and it would be awesome if you describe how you are using headers (what do you use them for?).
Some of these had more descriptive names, but the apache software foundation doesn't allow names with "Kafka" as part of the name because it's a protected trademark apparently.
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.
No it doesn't support avro yet, but this is being worked on and we think this could be added in 1.2 already! I added a note about the supported message formats in the readme.
We don't have any expectations or force to make money with Kowl. Besides that we already use Kowl at our company where engineers use it with joy in their daily business. We don't only get valuable feedback from colleagues who use Kowl, but our employer does also sponsor our efforts with working time. If it ultimately turns out to be not profitable at all we will simply open source everything I guess.