We are pleased to announce release 4.2.0 of the Cactus computational toolkit, an open source problem solving environment designed for scientists and engineers. This release includes various changes to the flesh, support for new architectures and comes bundled with supporting tools like GetComponents and Simfactory. In addition, bug fixes accumulated since the previous release in November 2012 have been included. Cactus provides computational scientists and engineers with a collaborative, modular and portable programming environment for parallel high performance computing. Cactus can make use of many other technologies for HPC, such as HDF5, PETSc and PAPI, and several application domains such as numerical relativity, computational fluid dynamics and quantum gravity are developing open community toolkits for Cactus. Cactus allows you to develop code in your language of choice: F77, F90, C, C++, Cuda and OpenCL are all supported — developers write their own components, which we call "thorns" which are connected together by the Cactus "flesh". Developers and users can take advantage of a selection of existing computational thorns, as well as a growing number of domain specific thorns. Cactus runs on a wide range (just about all) architectures and operating systems. Cactus is being used as the basis for numerous projects in computational science, and new technologies such as Grid computing, parallel file I/O, adaptive mesh refinement are very quickly available to our users. Cactus is developed and supported by an international team of computational and computer scientists, based largely at the Center for Computation & Technology at Louisiana State University. For more information about using or contributing to the Cactus Framework, please visit our web pages at . The Cactus Framework is partially supported by NSF 1212401/1212426/1212433/1212460 (Einstein Toolkit), 0903973/0903782/0904015 (CIGR), and also by NSF 0905046/0941653 (PetaCactus) and 0710874 (LONI Grid). The "4.2.0" Release Team on behalf of the Cactus Framework Group (2013-05-22) Significant Changes ------------------- * simfactory ** updates of various machine configurations ** remove existing default allocations; use local configuration to use these * Cactus flesh: ** Do not buffer output from thorn configuration scripts ** Introduce OPTIONAL_IFACTIVE for thorn dependencies ** Automatically activate required thorns ** Support IBM Blue Gene Q compilers ** Change the parameter parser to Piraha ** Implement CCTK_Error and friends (marked as non-returning for the compiler) ** Replace Cactus complex number type with C/C++ complex numbers ** Workaround for compiler-bug with Intel compiler and 'restrict'. In particular, for the current and recent Intel compilers (version 13), the 'restrict' keyword is disabled in Cactus code by default, because the compiler tends to produce wrong code otherwise. Release Trivia -------------- - The name of the release branches is Cactus_4.2.0 - The list of thorns included in this release can be downloaded from http://svn.cactuscode.org/Utilities/branches/Cactus_4.2.0/ThornLists/Cactus_4.2.0.th - The Einstein Toolkit (www.einsteintoolkit.org) released their current version "Gauss" today as well.