Ruby programming language
Ruby - is a programming language with complex, but expressive grammar and a basic class library with a rich and powerful API. Ruby incorporates features from languages such as Lisp, Perl, and Smalltalk, and uses a grammar that programmers familiar with C and Java languages can learn. Ruby is a fully object-oriented language, but it also supports procedural and functional programming styles. The cross-platform implementation of the interpreter is free. As its creator Yukihiro Matsumoto said: "Ruby was created to make programmers happy." It has many applications, including server programming (for these purposes, the Ruby on Rails framework is often used). It is used as a scripting language to extend capabilities and write programs. In addition to powerful features implemented in the language itself, it has a standard library and many additional libraries that implement multithreading, work with archives, matrices, dates, etc. The latest version is always available on the official website http://www.ruby-lang.org. In most Linux distributions, Ruby is available in the repository. Installation on Windows is done with just two clicks using the downloaded installation package.
I'm not an expert in Ruby, I had to start writing in it relatively recently, so I don't see the point in writing a full tutorial (as there are already plenty of them online), I will try to highlight only interesting/tangible things from the perspective of a PHP developer. =)
I will mainly write in a comparative mode with PHP (sorry, I've been using it for a long time), perhaps for some people it will be easier to understand through comparisons (personally, I understand things faster through comparisons).