diff --git a/CMakeLists.txt b/CMakeLists.txt
index 361018b..714d044 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -10,18 +10,26 @@ set(CMAKE_CXX_EXTENSIONS OFF)
 
 # --- CPM ---
 include(cmake/CPM.cmake)
-CPMFindPackage(
-    NAME tclap
-    GIT_REPOSITORY https://git.code.sf.net/p/tclap/code
-    VERSION 1.4.0
-    GIT_TAG 81b3d2a0c47895c22e9bb8c577f5ab521f76e5d2
-    DOWNLOAD_ONLY YES
-)
-if(tclap_ADDED AND NOT TARGET tclap)
+if(GUIX_BUILD)
+    find_path(_tclap_include UnlabeledValueArg.h PATH_SUFFIXES tclap REQUIRED)
     add_library(tclap INTERFACE IMPORTED)
     target_include_directories(
-        tclap SYSTEM INTERFACE ${tclap_SOURCE_DIR}/include
+        tclap SYSTEM INTERFACE ${_tclap_include} ${_tclap_include}/..
+    )
+else()
+    CPMFindPackage(
+        NAME tclap
+        GIT_REPOSITORY https://git.code.sf.net/p/tclap/code
+        GIT_TAG 81b3d2a0c47895c22e9bb8c577f5ab521f76e5d2
+        VERSION 1.4.0
+        DOWNLOAD_ONLY YES
     )
+    if(tclap_ADDED)
+        add_library(tclap INTERFACE IMPORTED)
+        target_include_directories(
+            tclap SYSTEM INTERFACE ${tclap_SOURCE_DIR}/include
+        )
+    endif()
 endif()
 
 set(VTK_COMPONENTS IOXML)
@@ -76,6 +84,7 @@ endif()
 
 add_executable(vtkdiff vtkdiff.cpp)
 target_link_libraries(vtkdiff tclap VTK::IOXML)
+install(TARGETS vtkdiff RUNTIME)
 
 # Set compiler helper variables
 if(${CMAKE_CXX_COMPILER_ID} MATCHES "Clang")
diff --git a/vtkdiff.cpp b/vtkdiff.cpp
index 4e08560..94df69f 100644
--- a/vtkdiff.cpp
+++ b/vtkdiff.cpp
@@ -1,7 +1,7 @@
 /**
  * \copyright
  * Copyright (c) 2015-2025, OpenGeoSys Community (http://www.opengeosys.org)
- *            Distributed under a Modified BSD License.
+ *            Distributed under the BSD 3-Clause "New" or "Revised" license.
  *              See accompanying file LICENSE.txt or
  *              http://www.opengeosys.org/project/license
  */
@@ -87,11 +87,11 @@ auto parseCommandLine(int argc, char* argv[]) -> Args
         "VtkDiff software.\n"
         "Copyright (c) 2015-2025, OpenGeoSys Community "
         "(http://www.opengeosys.org) "
-        "Distributed under a Modified BSD License. "
+        "Distributed under the BSD 3-Clause 'New' or 'Revised' License. "
         "See accompanying file LICENSE.txt or "
         "http://www.opengeosys.org/project/license",
         ' ',
-        "0.1");
+        "1.0.0");
 
     TCLAP::UnlabeledValueArg<std::string> vtk_input_a_arg(
         "input-file-a",