Lua - the most concise and powerful language needs to be in the list of languages #1
Description
Languages worth to be added because of their unique features:
Lua: because it is a most powerful concept among all languages I am aware of (many more as on the list)
Julia: because it is the only language I am currently aware of which supports any Unicode characters in naming of symbols
Rust: because of the idea to create executable files containing all what is needed to run them and utilizes re-usage of a huge amount of small chunks of functionality