When comparing Elixir vs PicoLisp, the Slant community recommends Elixir for most people. In the question“What are the best (productivity-enhancing, well-designed, and concise, rather than just popular or time-tested) programming languages?” Elixir is ranked 3rd while PicoLisp is ranked 66th. The most important reason people chose Elixir is:
Leverages the existing Erlang BEAM VM
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Great for concurrency
Leverages the existing Erlang BEAM VM

Pro Great getting started tutorials
The tutorials are very clear and concise (even for a person not used to functional programming). Plus they are also very mobile friendly.
Pro Powerful metaprogramming
Write code that writes code with Elixir macros. Macros make metaprogramming possible and define the language itself.
Pro Full access to Erlang functions
You can call Erlang functions directly without any overhead: https://elixir-lang.org/getting-started/erlang-libraries.html
Pro Scalability
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.
Pro Great as a first functional programming language!

Pro Great documentation
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.

Pro Syntax is similar to Ruby, making it familiar for people used to OOP
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.

Pro Easy to download libraries
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
Pro Integrated database and Prolog engine
Pro Fast code execution speed
One of the fastest code execution speeds compared to other Lisp dialects.
Pro Simplicity
Compared to other Lisp dialects, it's simple and doesn't have unnecessary features.
Pro Tacit
Code written in is short and easier to understand most of the time.
Pro Foreign function interface
The language has built-in FFI for C and also interfaces with java(via ersatz)
Cons
Con Deployment is still not as easy as it should be
Con Some design choices may seem strange
Some design choices could have been a little more appealing, for example: using "do...end" comes natural in Ruby for blocks but Elixir uses them for everything and it looks pretty weird:
Enum.map [1, 2, 3], fn(x) -> x * 2 end
or
receive do
{:hello, msg} -> msg
{:world, msg} -> "won't match"
end
Con Lack of Floating point data type
The language does not have floating point numbers only scaled fix-point numbers. Scaling of numbers is more work than directly working with floats.
