We are pleased to announce the tenth release (code name "Herschel" (Caroline)) of the Einstein Toolkit, an open, community developed software infrastructure for relativistic astrophysics. This release includes various improvements in the handling of external libraries (and with that, installations), and extensions of basis thorns (most notably HydroBase). In addition, bug fixes accumulated since the previous release in May 2014 have been included, and most of the source code repositories moved from svn (hosted by the ET directly) to git (hosted by BitBucket). For more detailed information about the "Herschel" release please read the long release announcement on the Einstein Toolkit web pages: http://einsteintoolkit.org/about/releases/ET_2014_11_announcement.php. The Einstein Toolkit is a collection of software components and tools for simulating and analyzing general relativistic astrophysical systems that builds on numerous software efforts in the numerical relativity community including CactusEinstein, the Carpet AMR infrastructure and the relativistic magneto-hydrodynamics code GRHydro. The Cactus Framework is used as the underlying computational infrastructure providing large-scale parallelization, general computational components, and a model for collaborative, portable code development. The toolkit includes modules to build complete codes for simulating black hole spacetimes as well as systems governed by relativistic magneto-hydrodynamics. The Einstein Toolkit uses a distributed software model and its different modules are developed, distributed, and supported either by the core team of Einstein Toolkit Maintainers, or by individual groups. Where modules are provided by external groups, the Einstein Toolkit Maintainers provide quality control for modules for inclusion in the toolkit and help coordinate support. The Einstein Toolkit Maintainers currently involve postdocs and faculty from six different institutions, and host weekly meetings that are open for anyone to join in. Guiding principles for the design and implementation of the toolkit include: open, community-driven software development; well thought out and stable interfaces; separation of physics software from computational science infrastructure; provision of complete working production code; training and education for a new generation of researchers. For more information about using or contributing to the Einstein Toolkit, or to join the Einstein Toolkit Consortium, please visit our web pages at http://einsteintoolkit.org. The Einstein Toolkit is primarily supported by NSF 1212401/1212426/1212433/1212460 (Einstein Toolkit), and also by 0905046/0941653 (PetaCactus) and 0710874 (LONI Grid). The Einstein Toolkit contains about 200 regression test cases. On a large portion of the tested machines, almost all of these test suites pass, using both MPI and OpenMP parallelization. The changes between this and the previous release include: === Larger changes since last release === * Repositories - Many repositories converted from Subversion to Git, including some reorganization of thorns within arrangements. - Deprecated components (still present) - ADMCoupling - ADMMacros - New components: - CUDA and OpenCL examples - PAPI - OpenBLAS - MemSpeed