Xl

XL was created in 2001 by Christophe de Dinechin to address the limitations of existing programming languages in terms of extensibility. It aimed to allow developers to create domain-specific languages and extend language syntax and semantics, simplifying complex programming tasks.

Strengths of XL included its extensibility and ability to create domain-specific languages. Weaknesses involved limited adoption and a smaller community, which impacted support and resources. Competitors included languages like Python, Ruby, and Lisp, which also offered flexibility and extensibility but had larger user bases and more extensive libraries.

An XL expert must have strong skills in language design, metaprogramming, and syntax extension. They should be proficient in creating and integrating domain-specific languages, understanding compiler construction, and managing language semantics. Familiarity with other extensible languages like Lisp or Forth can also be beneficial.