GNAT is a free, high-quality, complete compiler for Ada, integrated into the
GCC compiler system; the front-end and run-time are written in Ada. GNAT
supports Ada standards from 1995 to 2012, with on-going development into later
standards.

Ada was designed for embedded and real-time systems, it features include:
 * Strong static typing
 * Modular programming (via the package)
 * Encapsulation
 * Readability
 * Optional run-time checking
 * Concurrency (via tasks and protected objects), and message passing, as
   constructs in the language itself
 * Generics

Ada is designed for "Programming in the large", it suits rapid development, and
directly supports structured, object-oriented, generic, distributed and
concurrent programming paradigms. Ada is considered a Design Programming
Language, as a result of the expressive abstractions and features that informed
it's design. It's expressiveness allows users to clearly represent design
solutions modeled on their problem domain.