Erlang was released as open source over 10 years ago. In 1998. It did not get much attention at the time. Inside Ericsson Erlang was developed to manage the complexity of phone switches, and meeting the up-time requirements.
What appealed to me from the start about Erlang was how it seemed to be the product of telecoms people turning software developers, and not the product of software developers turning telecom. It had a completely different attitude toward system quality.
Most programming languages (or the communities around them) have some kind of mind-share you must get into to really work with the language. When it comes to Forth it is about minimalism. For Lisp it is about language adaption. Etc.
For Erlang it is about writing systems that can operate for decades. This colors the way you think in Erlang.
In a decade, your powersupply capacitors can burn up. In a decade your hard drives fail multiple times. In a decade hardware upgrades can/will happen on the running system. You are programming in the precense of errors. You are programming EXPECTING them to happen. Because failures WILL happen if your system runs for a decade. You just dont know when and where, just that it will be costly if your system isnt working.
The past years Erlang has gained huge traction in USA. It is known as the language to make good use out of multi-core cpus. Not much else.
Please dont forget the roots of Erlang. Multi-core scalability and easy clustering are positive side effects. But Erlang is all about robust systems.