I love that Erlang has been around a long time. Really starting to hate JS-based languages and tooling that becomes obsolete after a few years.
AndyL
Alchemist
I don’t have too much knowledge about Elixir yet, since I just started to read the book “Programming Elixir 1.3” and the course “The complete Elixir and Phoenix Bootcamp”. But what I had a few wow effects when I learned:
- Elixir has a built in doc generator which looks pretty cool
- Elixir has a built in testing framework
- Elixir will also test your doc examples! How AWESOME is that!
So, batteries are included (this is so amazing, especially if you know dozens of JavaScript libraries which become obsolete every couple of months)
What I also like is the functional programming aspect and pattern matching - which are both new to me.
I am so excited about the language that I want to read “Programming Elixir 1.3” and learn in my spare time as bad as I want to watch a great movie. I am looking forward to finish the book and start a few small projects in order to really become familiar with this language.
2
DianaOlympos
bbense
Watching beam.smp go to 2400% cpu in top on my server and knowing it’s actually doing something useful.
4
ibgib
- Community
- If someone asks a question, they get a thoughtful response no matter who they are or what the question. This includes what I’ve read on the Google Groups, on the (incredibly clean) GitHub issue tracker, and of course - here on Elixir Forum.
- Even though the documentation is so good (see next bullet section),I have yet to come across an RT(_)M response.
- This is a huge deal for me.
- Documentation
- Docs are first class citizens.
- Clear and simple guidance on documentation from the get-go.
- Bad documentation is a
- A bad error msg is a
- So the installation just works. The tutorials just work. The onboarding just works.
- Parallelism Juggernaut
- With the combination of the BEAM’s massively parallel, stateful-but-functional actors…
- Each process running with its own single-threaded execution in its own isolated memory space…
- All wrapped in an extremely elegant and thoughtful syntax…
- Wow.
1
bobbypriambodo
There are many reasons already stated in this thread, but as for me, coming from the (in)famous JavaScript world, there’s one thing that I really like about Elixir: that my code (thus far) is sequential.
I’ve just realized how awesome being able to write sequential code is. It really helps keeping your mind sane. In JS we try to mimic it using Promises, but it isn’t exactly the same. async/await is still in ES2016/ES7 so it’s kind of bummer that most platforms haven’t supported it yet.
It’s maybe the case that I haven’t used most of Elixir’s features yet, but it’s great to be able to query the DB (using Ecto) in one line and use it directly after that.
Several other reasons:
- Phoenix. It’s kind of nice to have decisions canonically made for you, especially when you’re learning.
- I love how fast dependency resolving and fetching are in Elixir. In contrast, I tried Haskell, but given up halfway trying to bootstrap an example Yesod project. The fetching and compiling the dependencies took so long.
And of course, echoing many in this thread, the community 
3
hec
sztosz
One thing I love the most is no god classes, or functions spanning across god knows how many lines. Splitting big chunks of code into small functions just come naturally here. You don’t do nested If’s and null checking. “With” is so freaking awesome 
I know that most of this are code smells in every language, but in Elixir when you write code you naturally avoid them, because code more then ever begs to be extracted to a separate function.
4
PatNowak
It’s gonna be a nice list 
- Immutability, which makes code easier to understand, to debug and to trace the flow
- Power of Erlang under the hood for free - lightweight processes, great communication system, whole OTP to use
- Flexible and powerful syntax - easy to code, but enables you to make great things with macros - world without breaks, long loops, spaghetti code and methods “all in one”
- Doctest - test your code with documentation, sound awesome, works even better
- Language improvements and Jose’s dedication - it’s different subject at all, but man! Such amount of work.
- Phoenix - because it’s Phoenix
6
harfangk
I love how Elixir keeps everything simple.
It has all the benefits of functional programming paradigm.
Then, Elixir uses only plain functions. No type classes, monads, and other increasingly complex abstractions in other functional languages that are nice but liable to go overboard.
Its pattern matching and OTP conventions lead developers to always break code into smaller parts, keeping complexity low and greatly delaying that eventual explosion of complexity.
3