The primary motivation for adding why3 is to support the upcoming SPARK 2014 port. However, SPARK 2014 requires a custom version. In time the customizations should make it upstream, but currently the stock version cannot be used to build SPARK. They are also licensed differently (LGPL2 for stock, GPLv3 for SPARK version). Rather than force people that find why3 useful on their own to accept a custom version, both are offered although they currently conflict. Why3 has optional dependencies on coq, isabelle, and frama-c, and all three have issus: * coq rebuilds its libraries in $LOCALBASE, could be issue with coq * isabella currently has a broken dependency (sjsml) and only for i386 when it's not. Updating to 2013-2 version failed, as did trying to build it with polyml instead of sjsml * frama-c is fine, but the plugin code in why3 is still experimental and upstream recommends that it not be used. ============================================================== Why3 is a platform for deductive program verification. It provides a rich language for specification and programming, called WhyML, and relies on external theorem provers, both automated and interactive, to discharge verification conditions. Why3 comes with a standard library of logical theories (integer and real arithmetic, Boolean operations, sets and maps, etc.) and basic programming data structures (arrays, queues, hash tables, etc.). A user can write WhyML programs directly and get correct-by- construction OCaml programs through an automated extraction mechanism. WhyML is also used as an intermediate language for the verification of C, Java, or Ada programs. Why3 is a complete reimplementation of the former Why platform. Among the new features are: numerous extensions to the input language, a new architecture for calling external provers, and a well-designed API, allowing to use Why3 as a software library. An important emphasis is put on modularity and genericity, giving the end user a possibility to easily reuse Why3 formalizations or to add support for a new external prover if wanted.