diff --git a/.github/workflows/netbsd.yml b/.github/workflows/netbsd.yml
new file mode 100644
index 00000000..01340440
--- /dev/null
+++ b/.github/workflows/netbsd.yml
@@ -0,0 +1,26 @@
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+
+jobs:
+  test:
+    runs-on: macos-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: cross-platform-actions/action@v0.22.0
+        env:
+          PKG_PATH: 'https://cdn.NetBSD.org/pub/pkgsrc/packages/NetBSD/amd64/9.3/All'
+        with:
+          operating_system: netbsd
+          version: '9.3' #TODO: bump to 10.0
+          run: |
+            pkg_add clang libLLVM gmake bash diffutils
+            gmake
+            ./runtests.sh --verbose"
+            ./runtests.sh --verbose --verbose"
+            gmake clean
+            ./compare_compilers.sh
+            gmake clean
+            ./compare_compilers.sh
diff --git a/Makefile.posix b/Makefile.posix
index 37a66f91..b934b247 100644
--- a/Makefile.posix
+++ b/Makefile.posix
@@ -7,6 +7,7 @@ LLVM_CONFIG ?= $(shell \
 	|| which /usr/local/opt/llvm@13/bin/llvm-config \
 	|| which llvm-config-11 \
 	|| which /usr/local/opt/llvm@11/bin/llvm-config \
+	|| which /usr/pkg/libexec/libLLVM/llvm-config \
 	)
 CFLAGS += $(shell $(LLVM_CONFIG) --cflags)
 CFLAGS += -gdwarf-4  # https://github.com/llvm/llvm-project/issues/56550
@@ -14,7 +15,10 @@ LDFLAGS ?= $(shell $(LLVM_CONFIG) --ldflags --libs)
 
 ifeq ($(CC),cc)
 	# default c compiler --> use clang
-	CC := $(shell $(LLVM_CONFIG) --bindir)/clang
+	CC := $(shell \
+	which `$(LLVM_CONFIG) --bindir`/clang \
+	|| which clang \
+	)
 endif
 
 all: jou compile_flags.txt
@@ -26,10 +30,10 @@ compile_flags.txt:
 config.h:
 	@v=`$(LLVM_CONFIG) --version`; case "$$v" in 11.*|13.*|14.*) ;; *) echo "Error: Found unsupported LLVM version $$v. Only LLVM 11, 13 and 14 are supported."; exit 1; esac
 	echo "// auto-generated by Makefile" > config.h
-	echo "#define JOU_CLANG_PATH \"$(shell $(LLVM_CONFIG) --bindir)/clang\"" >> config.h
+	echo "#define JOU_CLANG_PATH \"$(shell which `$(LLVM_CONFIG) --bindir`/clang || which clang)\"" >> config.h
 
 obj/%.o: src/%.c $(wildcard src/*.h) config.h
-	mkdir -vp obj && $(CC) -c $(CFLAGS) $< -o $@
+	mkdir -p obj && $(CC) -c $(CFLAGS) $< -o $@
 
 jou: $(SRC:src/%.c=obj/%.o)
 	$(CC) $(CFLAGS) $^ -o $@ $(LDFLAGS)
@@ -37,7 +41,7 @@ jou: $(SRC:src/%.c=obj/%.o)
 config.jou:
 	echo "# auto-generated by Makefile" > config.jou
 	echo "def get_jou_clang_path() -> byte*:" >> config.jou
-	echo "    return \"$(shell $(LLVM_CONFIG) --bindir)/clang\"" >> config.jou
+	echo "    return \"$(shell which `$(LLVM_CONFIG) --bindir`/clang || which clang)\"" >> config.jou
 
 self_hosted_compiler: jou config.jou $(wildcard self_hosted/*.jou)
 	./jou -o $@ --linker-flags "$(LDFLAGS)" self_hosted/main.jou
diff --git a/README.md b/README.md
index 1d205bf4..731cce90 100644
--- a/README.md
+++ b/README.md
@@ -164,6 +164,12 @@ MacOS support is new. Please create an issue if something doesn't work.
 
 </details>
 
+<details> <summary>NetBSD</summary>
+
+Additionally, there is support for NetBSD on an experimental
+basis. Packages `clang`, `libLLVM`, `gmake` and `bash` are required.
+
+</details>
 
 ## Updating to the latest version of Jou
 
diff --git a/compare_compilers.sh b/compare_compilers.sh
index 575ce24a..ab2eb2d9 100755
--- a/compare_compilers.sh
+++ b/compare_compilers.sh
@@ -37,13 +37,18 @@ if [ ${#actions[@]} = 0 ]; then
 fi
 
 rm -rf tmp/compare_compilers
-mkdir -vp tmp/compare_compilers
+mkdir -p tmp/compare_compilers
 
 YELLOW="\x1b[33m"
 GREEN="\x1b[32m"
 RED="\x1b[31m"
 RESET="\x1b[0m"
 
+DIFF=$(which gdiff || which diff)
+if [[ x"$($DIFF --help | grep -- --color)" != x ]]; then
+    diff_color="--color=always"
+fi
+
 function append_line()
 {
     local file="$1"
@@ -87,7 +92,7 @@ echo "Compiling the self-hosted compiler..."
 if [[ "$OS" =~ Windows ]]; then
     mingw32-make self_hosted_compiler.exe
 else
-    make self_hosted_compiler
+    $(which gmake || which make) self_hosted_compiler
 fi
 
 for file in ${files[@]}; do
@@ -126,7 +131,7 @@ for action in ${actions[@]}; do
             echo "  Compilers behave differently as expected (listed in $error_list_file)"
         fi
     else
-        if diff -u --color=always tmp/compare_compilers/compiler_written_in_c.txt tmp/compare_compilers/self_hosted.txt; then
+        if $DIFF -u $diff_color tmp/compare_compilers/compiler_written_in_c.txt tmp/compare_compilers/self_hosted.txt; then
             echo "  Compilers behave the same as expected"
         else
             if [ $fix = yes ]; then
diff --git a/examples/x11_window.jou b/examples/x11_window.jou
index c79937ec..74280e4b 100644
--- a/examples/x11_window.jou
+++ b/examples/x11_window.jou
@@ -1,7 +1,9 @@
-# To run this program, you need linux:
+# To run this program, you need a system with X11:
 #
+#   Linux:
 #   $ ./jou --linker-flags "-lX11" examples/x11_window.jou
-#
+#   NetBSD:
+#   $ ./jou --linker-flags "-L/usr/X11R7/lib -Wl,-R/usr/X11R7/lib -lX11" examples/x11_window.jou
 
 declare usleep(x: int) -> int
 
diff --git a/runtests.sh b/runtests.sh
index 996e3964..29c17fe3 100755
--- a/runtests.sh
+++ b/runtests.sh
@@ -58,9 +58,13 @@ while [ $# != 0 ]; do
     esac
 done
 
-if [ $valgrind = yes ] && [[ "$OS" =~ Windows ]]; then
-    echo "valgrind doesn't work on Windows." >&2
-    exit 2
+if [ $valgrind = yes ]; then
+    case "${OS:=$(uname)}" in
+        Windows*|NetBSD*)
+            echo "valgrind doesn't work on $OS." >&2
+            exit 2
+            ;;
+    esac
 fi
 
 if [ $run_make = yes ]; then
@@ -68,7 +72,7 @@ if [ $run_make = yes ]; then
         source activate
         mingw32-make
     else
-        make
+        eval $(which gmake || which make)
     fi
 fi
 
@@ -206,12 +210,17 @@ function run_test()
 
     printf "\n\n\x1b[33m*** Command: %s ***\x1b[0m\n\n" "$command" > $diffpath
 
-    if diff --text -u --color=always <(
+    DIFF=$(which gdiff || which diff)
+    if [[ x"$($DIFF --help | grep -- --color)" != x ]]; then
+        diff_color="--color=always"
+    fi
+
+    if $DIFF --text -u $diff_color <(
         generate_expected_output $joufile $correct_exit_code | tr -d '\r'
     ) <(
         export PATH="$PWD:$PATH"
         ulimit -v 500000 2>/dev/null
-        bash -c "$command; echo Exit code: \$?" 2>&1 | post_process_output $joufile | tr -d '\r'
+        sh -c "$command; echo Exit code: \$?" 2>&1 | post_process_output $joufile | tr -d '\r'
     ) &>> $diffpath; then
         show_ok "$command"
         rm -f $diffpath
diff --git a/self_hosted/create_llvm_ir.jou b/self_hosted/create_llvm_ir.jou
index 9ab42a77..1ecf2545 100644
--- a/self_hosted/create_llvm_ir.jou
+++ b/self_hosted/create_llvm_ir.jou
@@ -800,6 +800,8 @@ class AstToIR:
             name = "_jou_windows_startup"
         elif MACOS:
             name = "_jou_macos_startup"
+        elif NETBSD:
+            name = "_jou_netbsd_startup"
         else:
             return
 
@@ -817,7 +819,7 @@ class AstToIR:
         self->llvm_function = self->declare_function(sig)
         self->new_block("start")
 
-        if (WINDOWS or MACOS) and strcmp(sig->name, "main") == 0 and not sig->is_method():
+        if (WINDOWS or MACOS or NETBSD) and strcmp(sig->name, "main") == 0 and not sig->is_method():
             self->call_the_special_startup_function()
 
         # Allocate all local variables at the start of the function.
diff --git a/self_hosted/main.jou b/self_hosted/main.jou
index 3e29b028..c5d75170 100644
--- a/self_hosted/main.jou
+++ b/self_hosted/main.jou
@@ -178,6 +178,9 @@ class Compiler:
         if MACOS:
             self->automagic_files[1] = malloc(strlen(self->stdlib_path) + 40)
             sprintf(self->automagic_files[1], "%s/_macos_startup.jou", self->stdlib_path)
+        if NETBSD:
+            self->automagic_files[1] = malloc(strlen(self->stdlib_path) + 40)
+            sprintf(self->automagic_files[1], "%s/_netbsd_startup.jou", self->stdlib_path)
 
     def parse_all_files(self) -> None:
         queue: ParseQueueItem* = malloc(50 * sizeof queue[0])
diff --git a/src/codegen.c b/src/codegen.c
index 470cf29b..a596d70a 100644
--- a/src/codegen.c
+++ b/src/codegen.c
@@ -414,14 +414,16 @@ static int find_block(const CfGraph *cfg, const CfBlock *b)
     assert(0);
 }
 
-#if defined(_WIN32) || defined(__APPLE__)
+#if defined(_WIN32) || defined(__APPLE__) || defined(__NetBSD__)
 static void codegen_call_to_the_special_startup_function(const struct State *st)
 {
     const char *name;
-#ifdef _WIN32
+#if defined _WIN32
     name = "_jou_windows_startup";
-#else
+#elif defined __APPLE__
     name = "_jou_macos_startup";
+#else
+    name = "_jou_netbsd_startup";
 #endif
 
     LLVMTypeRef functype = LLVMFunctionType(LLVMVoidType(), NULL, 0, false);
@@ -448,7 +450,7 @@ static void codegen_function_or_method_def(struct State *st, const CfGraph *cfg)
     assert(cfg->all_blocks.ptr[0] == &cfg->start_block);
     LLVMPositionBuilderAtEnd(st->builder, blocks[0]);
 
-#if defined(_WIN32) || defined(__APPLE__)
+#if defined(_WIN32) || defined(__APPLE__) || defined(__NetBSD__)
     if (!get_self_class(&cfg->signature) && !strcmp(cfg->signature.name, "main"))
         codegen_call_to_the_special_startup_function(st);
 #endif
diff --git a/src/evaluate.c b/src/evaluate.c
index f598d39b..dccf373a 100644
--- a/src/evaluate.c
+++ b/src/evaluate.c
@@ -17,6 +17,13 @@ int get_special_constant(const char *name)
             return 0;
         #endif
     }
+    if (!strcmp(name, "NETBSD")) {
+        #ifdef __NetBSD__
+            return 1;
+        #else
+            return 0;
+        #endif
+    }
     return -1;
 }
 
diff --git a/src/main.c b/src/main.c
index 8589a776..fddfd1e2 100644
--- a/src/main.c
+++ b/src/main.c
@@ -461,6 +461,9 @@ int main(int argc, char **argv)
 #ifdef __APPLE__
     include_special_stdlib_file(&compst, "_macos_startup.jou");
 #endif
+#ifdef __NetBSD__
+    include_special_stdlib_file(&compst, "_netbsd_startup.jou");
+#endif
 
     parse_file(&compst, command_line_args.infile, NULL);
     parse_all_pending_files(&compst);
diff --git a/src/update.c b/src/update.c
index bd44e896..e6f52785 100644
--- a/src/update.c
+++ b/src/update.c
@@ -61,7 +61,7 @@ void update_jou_compiler()
         fail();
 #else
     confirm("Run \"git pull && make\"?");
-    if (system("git pull && make"))
+    if (system("git pull && `which gmake || which make`"))
         fail();
 #endif
 
diff --git a/stdlib/_netbsd_startup.jou b/stdlib/_netbsd_startup.jou
new file mode 100644
index 00000000..2859a865
--- /dev/null
+++ b/stdlib/_netbsd_startup.jou
@@ -0,0 +1,16 @@
+# A call to the _jou_netbsd_startup() function is inserted to the
+# start of every Jou program when compiling for NetBSD.
+
+declare global __sF: byte[456]
+global stdin: void*
+global stdout: void*
+global stderr: void*
+
+def _jou_netbsd_startup() -> None:
+    stdin = &__sF[0*152]
+    stdout = &__sF[1*152]
+    stderr = &__sF[2*152]
+
+declare __errno() -> int*
+def __errno_location() -> int*:
+    return __errno()
diff --git a/tests/should_succeed/compiler_cli.jou b/tests/should_succeed/compiler_cli.jou
index abf56f03..a9b0b55a 100644
--- a/tests/should_succeed/compiler_cli.jou
+++ b/tests/should_succeed/compiler_cli.jou
@@ -88,7 +88,7 @@ def main() -> int:
 
     # Compile a GUI program
     if not (WINDOWS or MACOS):
-        ret = system("./jou -o /dev/null --linker-flags \"-lX11\" examples/x11_window.jou")
+        ret = system("./jou -o /dev/null --linker-flags \"-L/usr/X11R7/lib -lX11\" examples/x11_window.jou")
         assert ret == 0
 
     # Compile a program with a memory leak.