Ada is described as '2012 is the next generation of the world’s premier programming language for engineering safe, secure and reliable software' and is an app in the Development category. There are more than 25 alternatives to Ada for a variety of platforms, including Windows, Linux, Mac, BSD and Android. The best alternative is Python, which is both free and Open Source. Other great apps like Ada are Java (Free Personal, Open Source), PHP (Free, Open Source), C (programming language) (Free, Open Source) and C++ (Free, Open Source).
C++ is a statically typed, free-form, multi-paradigm, compiled, general-purpose, powerful programming language. It is regarded as an intermediate-level language, as it comprises a combination of both high-level and low-level language features.
Ruby is a dynamic, reflective, general purpose object-oriented programming language that combines syntax inspired by Perl with Smalltalk-like features. Ruby originated in Japan during the mid-1990s and was initially developed and designed by Yukihiro "Matz" Matsumoto.
Haskell is an advanced purely-functional programming language. An open-source product of more than twenty years of cutting-edge research, it allows rapid development of robust, concise, correct software.