diff --git a/CMakeLists.txt b/CMakeLists.txt
index c448df78..67f95b0e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,4 @@
-CMAKE_MINIMUM_REQUIRED(VERSION 2.6)
+CMAKE_MINIMUM_REQUIRED(VERSION 3.5)
 
 PROJECT(LibSL)
 
@@ -28,6 +28,7 @@ OPTION(LIBSL_USE_GLFW              "Use glfw" OFF)
 OPTION(LIBSL_USE_GLUT              "Use glut" ON)
 OPTION(LIBSL_BUILD_GLFW            "Build glfw from source" OFF)
 OPTION(LIBSL_POWER_USER            "Power user mode (reserved, do not use)" OFF)
+OPTION(LIBSL_BUILD_TESTS           "Build LibSL tests" ON)
 
 ADD_DEFINITIONS(-DANDROID)
 
@@ -54,6 +55,7 @@ OPTION(LIBSL_USE_GLFW              "Use glfw" OFF)
 OPTION(LIBSL_USE_GLUT              "Use glut" ON)
 OPTION(LIBSL_BUILD_GLFW            "Build glfw from source" OFF)
 OPTION(LIBSL_POWER_USER            "Power user mode (reserved, do not use)" OFF)
+OPTION(LIBSL_BUILD_TESTS           "Build LibSL tests" ON)
 
 else(EMSCRIPTEN)
 
@@ -115,6 +117,7 @@ OPTION(LIBSL_BUILD_GLUX            "Build gluX"   ON)
 OPTION(LIBSL_BUILD_LIBARCHIVE      "Build libarchive"   OFF)
 OPTION(LIBSL_USE_GLUX              "Use gluX with LibSL_gl"   ON)
 OPTION(LIBSL_POWER_USER            "Power user mode (reserved, do not use)" OFF)
+OPTION(LIBSL_BUILD_TESTS           "Build LibSL tests" ON)
 
 endif(WASI)
 
@@ -174,7 +177,7 @@ INCLUDE_DIRECTORIES(
 			${CMAKE_CURRENT_SOURCE_DIR}/src/libs/src/SQLite
 			${CMAKE_CURRENT_SOURCE_DIR}/src/libs/src/qhull/src/libqhull_r
 			${CMAKE_CURRENT_SOURCE_DIR}/src/libs/src/rply
-      ${CMAKE_CURRENT_SOURCE_DIR}/src/libs/src/glfw/include
+			${CMAKE_CURRENT_SOURCE_DIR}/src/libs/src/glfw/include
 			)
 
 if (LIBSL_ENABLE_NVIDIA_CG)
diff --git a/libsl-config.cmake b/libsl-config.cmake
index 3f8bb358..c71de70a 100644
--- a/libsl-config.cmake
+++ b/libsl-config.cmake
@@ -548,7 +548,7 @@ IF (NOT TARGET AntTweakBar)
 	${OPENGL_LIBRARIES}
 	${X11_LIBRARIES}
 	)
-  ENDIF(APPLE)
+  ENDIF(NOT APPLE)
   #IF(APPLE)
   #    ADD_DEFINITIONS(-D_MACOSX)
   #    ADD_DEFINITIONS(-D__PLACEMENT_NEW_INLINE)
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 6d4a7e9c..59e4f3be 100755
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1,4 +1,4 @@
-CMAKE_MINIMUM_REQUIRED(VERSION 2.6)
+CMAKE_MINIMUM_REQUIRED(VERSION 3.5)
 
 # MESSAGE(STATUS "[in LibSL/src/]")
 
@@ -27,7 +27,7 @@ endif(LIBSL_BUILD_TOOLS)
 
 if (NOT WASI)
 ADD_SUBDIRECTORY(tests)
-endif(WASI)
+endif(NOT WASI)
 
 if(LIBSL_BUILD_TUTORIALS)
 ADD_SUBDIRECTORY(tutorials)
diff --git a/src/LibSL/Image/ImageFormat_PNG.cpp b/src/LibSL/Image/ImageFormat_PNG.cpp
index 7a7bb0f7..c3f6003f 100755
--- a/src/LibSL/Image/ImageFormat_PNG.cpp
+++ b/src/LibSL/Image/ImageFormat_PNG.cpp
@@ -220,8 +220,6 @@ void NAMESPACE::ImageFormat_PNG::save(const char *fname,const NAMESPACE::Image *
 
 //---------------------------------------------------------------------------
 
-#ifndef EMSCRIPTEN // SL 2025-04-17 hotfix as this result in Emscripten compilation error
-
 template <typename TChar>
 void write_data_stream(png_structp png_ptr, png_bytep data, png_size_t length)
 {
@@ -313,8 +311,6 @@ void NAMESPACE::ImageFormat_PNG::save<std::ostream::char_type>(
     const NAMESPACE::Image *img,
     const std::map<std::string,std::string>& key_value_text) const;
 
-#endif
-
 //---------------------------------------------------------------------------
 
 void NAMESPACE::ImageFormat_PNG::save(const char *fname, const NAMESPACE::Image *img) const
diff --git a/src/LibSL/Image/ImageFormat_PNG.h b/src/LibSL/Image/ImageFormat_PNG.h
index e9f8a486..578d65ef 100755
--- a/src/LibSL/Image/ImageFormat_PNG.h
+++ b/src/LibSL/Image/ImageFormat_PNG.h
@@ -64,13 +64,10 @@ namespace LibSL {
       void        save(const char*, const Image*, const std::map<std::string,std::string>& key_value_text) const;
       Image*      load(const char*, std::map<std::string, std::string>& _key_value_text)                   const;
 
-      #ifndef EMSCRIPTEN // SL 2025-04-17 hotfix as this result in Emscripten compilation error
-      // NS 2023-01-12: new interface to save in streams
       template<typename TChar>
       void        save(std::basic_ostream<TChar>&,
                        const Image*,
                        const std::map<std::string,std::string>& key_value_text) const;
-      #endif
     };
 
   } //namespace LibSL::Image
diff --git a/src/build/UseCXX11.cmake b/src/build/UseCXX11.cmake
index d6550da8..dfd318c7 100755
--- a/src/build/UseCXX11.cmake
+++ b/src/build/UseCXX11.cmake
@@ -1,5 +1,5 @@
 ################################################################################
-CMake_Minimum_Required(VERSION 2.6.3)
+CMake_Minimum_Required(VERSION 3.5)
 ################################################################################
 
 # The method used here is a bit involved and incomplete, so feel free to improve it!
diff --git a/src/build/UseCXX11_clang.cmake b/src/build/UseCXX11_clang.cmake
index 5c60ed12..95035fab 100644
--- a/src/build/UseCXX11_clang.cmake
+++ b/src/build/UseCXX11_clang.cmake
@@ -1,5 +1,5 @@
 ################################################################################
-CMake_Minimum_Required(VERSION 2.8.0)
+CMake_Minimum_Required(VERSION 3.5)
 ################################################################################
 
 # TODO: Set C Compiler Flags
diff --git a/src/libs/src/OpenNL/CMakeLists.txt b/src/libs/src/OpenNL/CMakeLists.txt
index 9ca9c9cc..776c2164 100755
--- a/src/libs/src/OpenNL/CMakeLists.txt
+++ b/src/libs/src/OpenNL/CMakeLists.txt
@@ -2,7 +2,7 @@
 #      CMake version checks
 ######################################
 if(COMMAND cmake_minimum_required)
-   cmake_minimum_required(VERSION 2.4)
+   cmake_minimum_required(VERSION 3.5)
 endif(COMMAND cmake_minimum_required)
 
 if(COMMAND cmake_policy)
diff --git a/src/libs/src/anttweakbar/CMakeLists.txt b/src/libs/src/anttweakbar/CMakeLists.txt
index 5152c18a..3096af22 100755
--- a/src/libs/src/anttweakbar/CMakeLists.txt
+++ b/src/libs/src/anttweakbar/CMakeLists.txt
@@ -1,4 +1,4 @@
-CMAKE_MINIMUM_REQUIRED(VERSION 2.6)
+CMAKE_MINIMUM_REQUIRED(VERSION 3.5)
 
 PROJECT(AntTweakBar)
 
diff --git a/src/libs/src/glfw/CMakeLists.txt b/src/libs/src/glfw/CMakeLists.txt
index 1ded78b5..7682a803 100755
--- a/src/libs/src/glfw/CMakeLists.txt
+++ b/src/libs/src/glfw/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.0)
+cmake_minimum_required(VERSION 3.5)
 
 project(GLFW VERSION 3.3.2 LANGUAGES C)
 
diff --git a/src/libs/src/glux/CMakeLists.txt b/src/libs/src/glux/CMakeLists.txt
index 1a7ca7e2..b7d2379f 100755
--- a/src/libs/src/glux/CMakeLists.txt
+++ b/src/libs/src/glux/CMakeLists.txt
@@ -1,4 +1,4 @@
-CMAKE_MINIMUM_REQUIRED(VERSION 2.6)
+CMAKE_MINIMUM_REQUIRED(VERSION 3.5)
 PROJECT(glux)
 
 OPTION(GLUX_BUILD_SAMPLES "Build gluX sample programs" OFF)
diff --git a/src/libs/src/hashlibpp/CMakeLists.txt b/src/libs/src/hashlibpp/CMakeLists.txt
index 133d382e..02228243 100755
--- a/src/libs/src/hashlibpp/CMakeLists.txt
+++ b/src/libs/src/hashlibpp/CMakeLists.txt
@@ -1,4 +1,4 @@
-CMAKE_MINIMUM_REQUIRED(VERSION 2.6)
+CMAKE_MINIMUM_REQUIRED(VERSION 3.5)
 PROJECT(hashlibpp)
 
 SET(LIBH_SOURCES 
diff --git a/src/libs/src/jpeg/CMakeLists.txt b/src/libs/src/jpeg/CMakeLists.txt
index 9e9a6ee6..fefc861f 100755
--- a/src/libs/src/jpeg/CMakeLists.txt
+++ b/src/libs/src/jpeg/CMakeLists.txt
@@ -1,4 +1,4 @@
-CMAKE_MINIMUM_REQUIRED(VERSION 2.6)
+CMAKE_MINIMUM_REQUIRED(VERSION 3.5)
 PROJECT(jpeg)
 
 SET(LIBJPEG_SOURCES 
diff --git a/src/libs/src/lib3ds/CMakeLists.txt b/src/libs/src/lib3ds/CMakeLists.txt
index cef33c30..aaf86e78 100755
--- a/src/libs/src/lib3ds/CMakeLists.txt
+++ b/src/libs/src/lib3ds/CMakeLists.txt
@@ -1,4 +1,4 @@
-CMAKE_MINIMUM_REQUIRED(VERSION 2.6)
+CMAKE_MINIMUM_REQUIRED(VERSION 3.5)
 PROJECT(3ds)
 
 SET(LIB3DS_SOURCES 
diff --git a/src/libs/src/newmat/CMakeLists.txt b/src/libs/src/newmat/CMakeLists.txt
index 3b07fb22..d7ce1c1a 100755
--- a/src/libs/src/newmat/CMakeLists.txt
+++ b/src/libs/src/newmat/CMakeLists.txt
@@ -1,4 +1,4 @@
-CMAKE_MINIMUM_REQUIRED(VERSION 2.6)
+CMAKE_MINIMUM_REQUIRED(VERSION 3.5)
 PROJECT(newmat)
 
 SET(NEWMAT_SOURCES 
diff --git a/src/libs/src/png/CMakeLists.txt b/src/libs/src/png/CMakeLists.txt
index fa5b5ce7..d64e2db6 100755
--- a/src/libs/src/png/CMakeLists.txt
+++ b/src/libs/src/png/CMakeLists.txt
@@ -1,4 +1,4 @@
-CMAKE_MINIMUM_REQUIRED(VERSION 2.6)
+CMAKE_MINIMUM_REQUIRED(VERSION 3.5)
 PROJECT(png)
 
 SET(LIBPNG_SOURCES
diff --git a/src/libs/src/qhull/CMakeLists.txt b/src/libs/src/qhull/CMakeLists.txt
index 95def930..3c5e7a49 100755
--- a/src/libs/src/qhull/CMakeLists.txt
+++ b/src/libs/src/qhull/CMakeLists.txt
@@ -35,7 +35,7 @@
 # $DateTime: 2012/02/21 22:41:40 $$Author: bbarber $
 
 project(qhull)
-cmake_minimum_required(VERSION 2.6)
+cmake_minimum_required(VERSION 3.5)
 
 # Define qhull_VERSION in CMakeLists.txt, Makefile, qhull-exports.def, qhull_p-exports.def, and qhull-warn.pri
 string(REGEX REPLACE ".* ([0-9]+) .*"
diff --git a/src/libs/src/tinyxml/CMakeLists.txt b/src/libs/src/tinyxml/CMakeLists.txt
index ce732ee9..7fe7d638 100755
--- a/src/libs/src/tinyxml/CMakeLists.txt
+++ b/src/libs/src/tinyxml/CMakeLists.txt
@@ -1,4 +1,4 @@
-CMAKE_MINIMUM_REQUIRED(VERSION 2.6)
+CMAKE_MINIMUM_REQUIRED(VERSION 3.5)
 PROJECT(tinyxml)
 
 SET(TINYXML_SOURCES 
diff --git a/src/tests/CMakeLists.txt b/src/tests/CMakeLists.txt
index c0fecb0f..1f0f844b 100755
--- a/src/tests/CMakeLists.txt
+++ b/src/tests/CMakeLists.txt
@@ -1,4 +1,4 @@
-# CMAKE_MINIMUM_REQUIRED(VERSION 2.6)
+# CMAKE_MINIMUM_REQUIRED(VERSION 3.5)
 PROJECT(TestLibSL)
 
 INCLUDE(${LibSL_DIR}/libsl-config.cmake)
@@ -60,11 +60,15 @@ endif(LIBSL_BUILD_GL)
 if(LIBSL_BUILD_GL4CORE)
 ADD_EXECUTABLE(test_sh_gl4core test_sh_gl4core.cpp test_sh_gl4core.fp test_sh_gl4core.vp test_sh_gl4core.h)
 TARGET_LINK_LIBRARIES(test_sh_gl4core LibSL LibSL_gl4core)
-SET_TARGET_PROPERTIES(test_sh_gl4core PROPERTIES COMPILE_DEFINITIONS "USE_GLUX;OPENGL4;OPENGLCORE")
+SET_TARGET_PROPERTIES(test_sh_gl4core PROPERTIES COMPILE_DEFINITIONS "USE_GLUX")
 endif(LIBSL_BUILD_GL4CORE)
 
+IF(LIBSL_USE_INSTALL_PREFIX)
+  SET(LIBSL_INSTALL_BIN_DIR "bin")
+ELSE()
+  SET(LIBSL_INSTALL_BIN_DIR "${CMAKE_SOURCE_DIR}/bin")
+ENDIF()
+
 INSTALL(TARGETS TestLibSL
-	RUNTIME DESTINATION ${CMAKE_SOURCE_DIR}/bin
-	LIBRARY DESTINATION ${LIBSL_INSTALL_LIB_DIR}
-	ARCHIVE DESTINATION ${LIBSL_INSTALL_LIB_DIR}
+	RUNTIME DESTINATION ${LIBSL_INSTALL_BIN_DIR}
 )