Celluloid VS Akka

Speaking as someone who has used Erlang longer than most, who created a pre-Elixir-like language for Erlang's BEAM VM, and who routinely listens to Carl Hewitt's rants about why Erlang actors are bad, and who tried to make a Ruby actor library after using innumerable other library-level actor solutions...

Celluloid

First-class distributed and multicore computing. Swift has first-class “actors” and “distributed” methods. Unison, Erlang, and Elixir are built with distributed being one of the #1 concerns. Though first-class is not super common and I don't really expect it to be because usually libraries are enough (e.g. Scala has Akka and is used WIDELY for distributed); whereas something like linear types and typed effects, you can't emulate in a library.

Akka is a library that implements the actor model for JVM languages. Mainly in Scala, but you can use it in Java too, and maybe others. It doesn't feel as ergonomic as Elixir, but if Elixir is too "out there" for the decision makers in your case, this might be a friendlier alternative.

Note Akka, the Java & friends framework, is working with the actor model and have as main inspiration Erlang to mimic some features of the BEAM on top of the JVM.

If I hear about Actor model, the first thing that comes to my mind is the popular Open Source library Akka.

Lightbend, the company owning Akka, recently shared a blog post signed by the CEO announcing a license change from Apache 2.0 to Business Source License 1.1, a proprietary license. You can already find it in this PR, merged a couple days ago.

Akka 2.6 is on the open source Apache license, that is unchanged (its not possible for Lightbend to change an existing license). Its only the new Akka 2.7 which has the BSL license, so as long as you don't upgrade you are fine. See https://github.com/akka/akka/pull/31561.

Here is Akka's dependency specification: https://github.com/akka/akka/blob/main/project/Dependencies....

How many of these would have to opt for this source available approach before Akka would no longer be sustainable?

I don't think that the Akka change is aimed at cloud providers. Akka is a toolkit for building highly concurrent, distributed, and resilient message-driven applications for Java and Scala [1]. It's not possible for AWS to offer their own "Akka service" the way they offered Redis through ElastiCache. This change affects companies that build software using Akka, many of which may not be software-focused. For example, here's a case study of an oilfield services company that uses Akka:

https://www.lightbend.com/blog/low-cpu-utilization-fortune-5...

[1] As found on https://akka.io/

> So Amazon can take free code, sell it as a slickly-packaged service, and not need to share anything.

Right, because they didn't change it. So what would there be to share anyway? 'Go to https://github.com/akka/akka'?

> but it does mean that at least every user has access to the code to make their "Akka Service" as good as Amazon's.

That code is meaningless. In this scenario we already established that Amazon is selling an unmodified copy of Akka as a Service (which, by the way, we will revisit this point later). And we already established, in your own words, that it's not about the code:

> Their secret sauce is "we have a Borg Cube's worth of datacenters, so we can run the same code as you at a lower price".

So what would the SSPL require, they publish their deployment scripts to their cloud datacentres? Like I said, that's meaningless.

> "Akka Service"

Final point. There's no such thing as an 'Akka Service'. Akka is a bunch of libraries. You link it into your JVM application. You don't run Akka separately, so by definition you can't offer it as a service (even if you're Amazon).

Hence my suggestion of AGPL, and heck let's be generous, let's add a commercial use exception for businesses with less than $20m revenue, similar to what they're doing now with the BSL. Except with my suggestion the software would stay as strong copyleft, most businesses would be happy with the commercial use exception, and a few would have to pay their fair share.

[1] https://news.ycombinator.com/item?id=32751373