Reminds of Paul Graham’s essay on Lisp being a secret weapon for Viaweb, Beating The Averages[1].

[1]: http://www.paulgraham.com/avg.html

There have been second hand report of the current leadership at Ericsson saying that opensourcing erlang was the worst decision they had taken. As it would have given way a massive competitive advantage.

There's pros and cons to these kind of things. "Best tool for the job" reasoned purely from a technical point of view isn't necessarily the "best tool for the job" when everything is factored in.

It's hard for me to judge one way or the other; I wasn't at Ericsson in 1998, or indeed, ever at Ericsson. I just figured that the language wasn't open source at the time and that they came back on their decision just a few year later were important bits missing from the previous comment.