Building Themis from source code # Building Themis from source is not recommended for casual or first-time use. Unless you really know what you are doing and why — install prebuilt Themis from packages. Building Themis Core # Dependencies # To build Themis on your own machine, you will need some common UNIX build tools: C compiler: GCC or Clang GNU Make Themis also requires either OpenSSL, LibreSSL, or BoringSSL to be installed.