Anyone who has written a technical book knows that in general they cost a lot in terms of time and don't generate great returns. The best case is probably if it boosts your consulting income or something to that effect.
I've never met Fred, but I feel his book "Learn You Some Erlang" is clearly in another category: it's a "labor of love". I can't speak to his precise motivations, but the book is so rich and thorough, that it's clearly something he worked way harder on than would have been strictly necessary just to whip out a quick book establishing himself as an Erlang Expert. Maybe it was "the Erlang book he wished he'd had when he got started"?
As such, it's one of the few tech books I've bought, and done so quite happily, in recent years.
Well this is technically the fourth one I'm working on. All are available for free online because I want these resources to be accessible first and foremost.
I've got:
Learn You Some Erlang, which has been published with No Starch Press. This was my first one, which I assume is the one you're talking about. Lots of drawings, something I no longer really have the time and energy for these days compared to early in my career. It's the big basics of Erlang. A bit dated now, particularly since the ecosystem evolved around it, but all the basics are still well-covered I think.
Erlang in Anger, only available as a self-published short e-book available for free, meant to teach people to operate Erlang in production.
Property-Based Testing with PropEr, Erlang, and Elixir; my latest published one (with Pragmatic programmers), covering property-based testing both with Erlang and Elixir at once. Pragprog have let me keep the initial website online, which only covered Erlang.
And Adopting Erlang is the latest one. We're still writing it (this time I'm a co-author rather than the sole author), and there's no physical or ISBN'd copy of it available at this point in time.
All of them have to be labours of love, just because it's a lot of work and effort, and at this point in my career, my name's well-known within the Erlang and Elixir communities, so you could say there are diminishing returns. I still enjoy writing though, it's just harder to make time.
I've never met Fred, but I feel his book "Learn You Some Erlang" is clearly in another category: it's a "labor of love". I can't speak to his precise motivations, but the book is so rich and thorough, that it's clearly something he worked way harder on than would have been strictly necessary just to whip out a quick book establishing himself as an Erlang Expert. Maybe it was "the Erlang book he wished he'd had when he got started"?
As such, it's one of the few tech books I've bought, and done so quite happily, in recent years.