"1) It would have never got widely used in the industry" Agreed. "2) We would have never got a free open source tool that helped kick-start many other compani

"1) It would have never got widely used in the industry" Agreed. "2) We would have never got a free open source tool that helped kick-start many other companies." Disagreed. A different open source tool would have gotten the attention and that would have helped kickstart many other companies. Pretty much every open source tool or library has equally open source alternatives, sometimes even just as popular alternatives. Elasticsearch is no exception, and its alternatives are about to get a surge in popularity. "You could say the same about Mongo. Imagine what impact it would have had on the startup world if Mongo wasn't a FOSS project." More startups would have used Postgres instead... Which probably they should have done anyway. Mongo only started to become usable for anything but raw streams of data, IMO, not long before it became source available. And even nowadays, I would still recommend Postgres (or any relational database) over Mongo for 95% of startups, even if it still were open source. That said, I know that that is not the case with Elasticsearch, which probably is the best among its alternatives.