Thank you for your feedback. I'm the author of the article and will review how I can improve this.

However, at a brief glance back at the article, The second sentence in the first paragraph says it's an "application server". Further below the illustration image, there's a text in bold that says "Eclipse GlassFish is now a production-ready, enterprise-grade platform".

So I'm really curious, whether the article didn't make it clear, or there was a lack of interest on your side.