Nim vs Elixir

There are generics, templates, macros in Nim. They can allow you to write new DSL for your application, or avoid all boilerplate stuff.

Checks your code at compile time.

With built-in "unittest" module you can create test with a very readable code.

Nim has a built-in VM, which executes macros and some other code at compile time. For example, you can check if you're on Windows, and Nim will generate code only for it.

Nim has "asyncdispatch" module, which allows you to write async applications.

The same code can be used for web, server, desktop and mobile.

Nim has a lot of common with Python in terms of syntax. Indentation-based syntax, for/while loops.

Imperative, OOP, functional programming in one language.

You can use Nim with any language that can be interfaced with C. There's a tool which helps you to create new C and C++ bindings for Nim - c2nim.
Also, you can use Nim with Objective C or even JavaScript (if you're compiling for these backends).

You don't need to deal with all those manual memory allocations, Nim can take care of it. But also you can use another GC, or tweak it for your real-time application or a game.

You only need to specify types in your procedures and objects - you don't need to specify type when you're creating a new variable (unless you're creating it without initialization).

You can use unicode names for variables, there is "unicode" module for operations with unicode.

writeLine(stdout, "hello") can be written as stdout.writeLine("hello")
proc add(a: int): int = a + 5 can be used like 6.add.echo or 6.add().echo()

Leverages the existing Erlang BEAM VM

The tutorials are very clear and concise (even for a person not used to functional programming). Plus they are also very mobile friendly.

Write code that writes code with Elixir macros. Macros make metaprogramming possible and define the language itself.

You can call Erlang functions directly without any overhead: https://elixir-lang.org/getting-started/erlang-libraries.html

Elixir programming is ideal for applications that have many users or are actively growing their audience. Elixir can easily cope with much traffic without extra costs for additional servers.
More details can be found here.

Elixir's documentation is very good. It covers everything and always helps solving any problem you may have. It's also always available from the terminal.

All of the benefits of Erlang; without as steep a learning curve of prolog based syntax. Elixir is heavily inspired by Ruby's syntax which many people love.

Comes with built in build tool called "mix". This will automatically download libraries and put them in the scope of the application when you add them to the "deps" function and run mix deps.get