.. _Prerequisites: Prerequisites ------------- VisIt's Source Code ~~~~~~~~~~~~~~~~~~~ For a released version """""""""""""""""""""" For building a released version of VisIt version 3.2.1 or earlier, you can download a windows installer that contains all that is necessary from the `downloads page `_. Look for the *Win 10/8/7 development* link for the particular version you want. The file will be named *visitdev3.2.1.exe* (or similar, based on version chosen). For building a released version of VisIt version 3.2.2 or newer, download the *Source* tgz file as well as the *Win 10 development* file which will be named *visit_windowsdev_3.2.2.zip* (or similar, based on version chosen). The .zip file contains all the prebuilt third party binaries needed for building VisIt on Windows. It is best to extract these files to the same folder so that *src* from the source tarball is peer to *windowsbuild* from the windows-dev zip file. For the latest development version """""""""""""""""""""""""""""""""" If you want to build the latest development version from our repository, you need to obtain source from the `visit repo `_, and the prebuilt third party dependencies from the `visit-deps repo `_ on GitHub. Other Software ~~~~~~~~~~~~~~ 1. `CMake `_ version 3.24 or greater. * Don't use the CMake included with cygwin if you plan on using the prebuilt third party libraries. 2. Visual Studio 2022 (VisIt 3.4.0 and newer) or Visual Studio 2017 * Needed if you want to use our prebuilt third party libraries. 3. `NSIS `_ *Optional* * For creating an installer for VisIt. NSIS 2 or 3 should work. 4. `Microsoft MPI `_. *Optional* * For building VisIt's parallel engine. Redistributable binaries and SDK's are needed, so download and install both msmpisdk.msi and msmpisetup.exe.