diff --git a/releasenotes.md b/releasenotes.md
index 9b5ef3c6b..6a7c04ddb 100644
--- a/releasenotes.md
+++ b/releasenotes.md
@@ -3,6 +3,8 @@
 ## 0.5.0 Change List
 
 ### Changes / improvements
+- 'exec' directive to run scripts at compile time.
+- Project key descriptions in --list command.
 - Added `init-lib` to simplify library creation.
 - Local `const` work like namespaced global `const`.
 - Added `$$atomic_fetch_*` builtins.
diff --git a/resources/testfragments/pwd2.c3 b/resources/testfragments/pwd2.c3
new file mode 100644
index 000000000..2e86a9102
--- /dev/null
+++ b/resources/testfragments/pwd2.c3
@@ -0,0 +1,3 @@
+module pwd;
+
+fn int getnum() => 3;
\ No newline at end of file
diff --git a/resources/testproject/run/run.md b/resources/testproject/scripts/scripts.md
similarity index 100%
rename from resources/testproject/run/run.md
rename to resources/testproject/scripts/scripts.md
diff --git a/src/build/build.h b/src/build/build.h
index 35bb081b7..7aad1e1a2 100644
--- a/src/build/build.h
+++ b/src/build/build.h
@@ -355,6 +355,7 @@ typedef struct BuildOptions_
 	const char *llvm_out;
 	const char *asm_out;
 	const char *obj_out;
+	const char *script_dir;
 	RelocModel reloc_model;
 	X86VectorCapability x86_vector_capability;
 	X86CpuSet x86_cpu_set;
@@ -429,6 +430,7 @@ typedef struct
 	const char *object_file_dir;
 	const char *ir_file_dir;
 	const char *asm_file_dir;
+	const char *script_dir;
 	bool run_after_compile;
 	bool generate_benchmark_runner;
 	bool generate_test_runner;
@@ -470,6 +472,7 @@ typedef struct
 	const char *testfn;
 	const char *cc;
 	const char *cflags;
+	const char **exec;
 	const char **csource_dirs;
 	const char **csources;
 	const char **feature_list;
diff --git a/src/build/build_internal.h b/src/build/build_internal.h
index 72918c209..cf5b5523e 100644
--- a/src/build/build_internal.h
+++ b/src/build/build_internal.h
@@ -25,6 +25,12 @@ static const char *wincrt_linking[3] = {
 	[WIN_CRT_STATIC] = "static",
 };
 
+static const char *trust_level[3] = {
+	[TRUST_NONE] = "none",
+	[TRUST_INCLUDE] = "include",
+	[TRUST_FULL] = "full",
+};
+
 static const char *optsizes[3] = {
 	[SIZE_OPTIMIZATION_NONE] = "none",
 	[SIZE_OPTIMIZATION_SMALL] = "small",
diff --git a/src/build/build_options.c b/src/build/build_options.c
index 294a2362d..7b41539b7 100644
--- a/src/build/build_options.c
+++ b/src/build/build_options.c
@@ -96,13 +96,12 @@ static void usage(void)
 	OUTPUT("  -O5                       - Unsafe, highest optimization, fast maths, single module, emit debug info.");
 	OUTPUT("  -Os                       - Unsafe, high optimization, small code, single module, no debug info.");
 	OUTPUT("  -Oz                       - Unsafe, high optimization, tiny code, single module, no debug info.");
-	OUTPUT("  -t1                       - Trust level 1 - don't allow $include nor $exec (default).");
-	OUTPUT("  -t2                       - Trust level 2 - allow $include but not $exec / exec directives.");
-	OUTPUT("  -t3                       - Trust level 3 - full trust, allow both include and exec.");
 	OUTPUT("  -D <name>                 - Add feature flag <name>.");
 	OUTPUT("  -U <name>                 - Remove feature flag <name>.");
+	OUTPUT("  --trust=<option>          - Trust level: none (default), include ($include allowed), full ($exec / exec allowed).");
 	OUTPUT("  --build-dir <dir>         - Override build output directory.");
 	OUTPUT("  --obj-out <dir>           - Override object file output directory.");
+	OUTPUT("  --script-dir <dir>        - Override the base directory for $exec.");
 	OUTPUT("  --llvm-out <dir>          - Override llvm output directory for '--emit-llvm'.");
 	OUTPUT("  --emit-llvm               - Emit LLVM IR as a .ll file per module.");
 	OUTPUT("  --asm-out <dir>           - Override asm output directory for '--emit-asm'.");
@@ -887,6 +886,11 @@ static void parse_option(BuildOptions *options)
 				options->win.sdk = check_dir(next_arg());
 				return;
 			}
+			if ((argopt = match_argopt("trust")))
+			{
+				options->trust_level = (TrustLevel) parse_multi_option(argopt, 3, trust_level);
+				return;
+			}
 			if ((argopt = match_argopt("wincrt")))
 			{
 				options->win.crt_linking = (WinCrtLinking)parse_multi_option(argopt, 3, wincrt_linking);
@@ -916,6 +920,12 @@ static void parse_option(BuildOptions *options)
 				options->obj_out = next_arg();
 				return;
 			}
+			if (match_longopt("script-dir"))
+			{
+				if (at_end() || next_is_opt()) error_exit("error: --script-dir needs a directory.");
+				options->script_dir = next_arg();
+				return;
+			}
 			if (match_longopt("llvm-out"))
 			{
 				if (at_end() || next_is_opt()) error_exit("error: --llvm-out needs a directory.");
@@ -1044,6 +1054,7 @@ BuildOptions parse_arguments(int argc, const char *argv[])
 		.single_module = SINGLE_MODULE_NOT_SET,
 		.files = NULL,
 		.build_dir = NULL,
+		.script_dir = NULL,
 
 	};
 	for (int i = DIAG_NONE; i < DIAG_WARNING_TYPE; i++)
diff --git a/src/build/builder.c b/src/build/builder.c
index 262931c44..375ee7523 100644
--- a/src/build/builder.c
+++ b/src/build/builder.c
@@ -312,6 +312,7 @@ static void update_build_target_from_options(BuildTarget *target, BuildOptions *
 		target->object_file_dir = options->obj_out ? options->obj_out : target->build_dir;
 		target->ir_file_dir = options->llvm_out ? options->llvm_out : target->build_dir;
 		target->asm_file_dir = options->asm_out ? options->asm_out : target->build_dir;
+		target->script_dir = options->script_dir ? options->script_dir : target->script_dir;
 	}
 	else
 	{
@@ -319,6 +320,8 @@ static void update_build_target_from_options(BuildTarget *target, BuildOptions *
 		target->object_file_dir = options->obj_out ? options->obj_out : file_append_path(target->build_dir, "tmp");
 		target->ir_file_dir = options->llvm_out ? options->llvm_out : file_append_path(target->build_dir, "llvm_ir");
 		target->asm_file_dir = options->asm_out ? options->asm_out : file_append_path(target->build_dir, "asm");
+		target->script_dir = options->script_dir ? options->script_dir : target->script_dir;
+		if (!target->script_dir) target->script_dir = "scripts";
 	}
 	switch (options->compile_option)
 	{
diff --git a/src/build/project.c b/src/build/project.c
index c6806bf96..7ebd71ce4 100644
--- a/src/build/project.c
+++ b/src/build/project.c
@@ -6,211 +6,116 @@
 #include "build_internal.h"
 #define MAX_SYMTAB_SIZE (1024 * 1024)
 
-const char *project_default_keys[] = {
-	"authors",
-	"benchfn",
-	"c-sources",
-	"cc",
-	"cflags",
-	"cpu",
-	"debug-info",
-	"dependencies",
-	"dependency-search-paths",
-	"features",
-	"fp-math",
-	"langrev",
-	"linked-libraries",
-	"linker-search-paths",
-	"link-args",
-	"link-libc",
-	"macossdk",
-	"memory-env",
-	"no-entry",
-	"opt",
-	"optlevel",
-	"optsize",
-	"output",
-	"panicfn",
-	"reloc",
-	"safe",
-	"single-module",
-	"soft-float",
-	"sources",
-	"strip-unused",
-	"symtab",
-	"system-linker",
-	"target",
-	"targets",
-	"testfn",
-	"trap-on-wrap",
-	"use-stdlib",
-	"version",
-	"warnings",
-	"wincrt",
-	"winsdk",
-	"x86cpu",
-	"x86vec",
-	"x86-stack-struct-return",
+const char *project_default_keys[][2] = {
+		{"authors", "Authors, optionally with email."},
+		{"benchfn", "Override the benchmark function."},
+		{"c-sources", "Set the C sources to be compiled."},
+		{"cc", "Set C compiler (defaults to 'cc')."},
+		{"cflags", "C compiler flags."},
+		{"cpu", "CPU name, used for optimizations in the compiler backend."},
+		{"debug-info", "Debug level: none, line-tables, full."},
+		{"dependencies", "C3 library dependencies for all targets."},
+		{"dependency-search-paths", "The C3 library search paths."},
+		{"exec", "Scripts run for all targets.."},
+		{"features", "Features enabled for all targets."},
+		{"fp-math", "Set math behaviour: `strict`, `relaxed` or `fast`."},
+		{"langrev", "Version of the C3 language used."},
+		{"linked-libraries", "Libraries linked by the linker for all targets."},
+		{"linker-search-paths", "Linker search paths."},
+		{"link-args", "Linker arguments for all targets."},
+		{"link-libc", "Link libc (default: true)."},
+		{"macossdk", "Set the directory for the MacOS SDK for cross compilation."},
+		{"memory-env", "Set the memory environment: normal, small, tiny, none."},
+		{"no-entry", "Do not generate (or require) a main function."},
+		{"opt", "Link libc (default: true)."},
+		{"optlevel", "Code optimization level: none, less, more, max."},
+		{"optsize", "Code size optimization: none, small, tiny."},
+		{"output", "Output location, relative to project file."},
+		{"panicfn", "Override the panic function."},
+		{"reloc", "Relocation model: none, pic, PIC, pie, PIE."},
+		{"safe", "Set safety (contracts, runtime bounds checking, null pointer checks etc) on or off."},
+		{"script-dir", "The directory where 'exec' is run."},
+		{"single-module", "Compile all modules together, enables more inlining."},
+		{"soft-float", "Output soft-float functions."},
+		{"sources", "Paths to project sources for all targets."},
+		{"strip-unused", "Strip unused code and globals from the output. (default: true)"},
+		{"symtab", "Sets the preferred symtab size."},
+		{"system-linker", "Use the system linker (default: no for cross compilation, yes otherwise)."},
+		{"target", "Compile for a particular architecture + OS target."},
+		{"targets", "Set of targets for the project."},
+		{"testfn", "Override the test function."},
+		{"trap-on-wrap", "Make signed and unsigned integer overflow generate a panic rather than wrapping."},
+		{"use-stdlib", "Include the standard library (default: true)."},
+		{"version", "Version using semantic versioning."},
+		{"warnings", "Warnings used for all targets."},
+		{"wincrt", "Windows CRT linking: none, static, dynamic (default)."},
+		{"winsdk", "Set the path to Windows system library files for cross compilation."},
+		{"x86cpu", "Set general level of x64 cpu: baseline, ssse3, sse4, avx1, avx2-v1, avx2-v2 (Skylake/Zen1+), avx512 (Icelake/Zen4+), native."},
+		{"x86vec", "Set max type of vector use: none, mmx, sse, avx, avx512, native."},
+		{"x86-stack-struct-return", "Return structs on the stack for x86."},
 };
 
 const int project_default_keys_count = ELEMENTLEN(project_default_keys);
 
-const char *project_default_descriptions[] = {
-	"Authors, optionally with email.",
-	"Override the benchmark function name.",
-	"Override C sources to be compiled.",
-	"Specify the C compiler.",
-	"Add flags for the C compiler.",
-	"CPU name, used for optimizations in the compiler backend.",
-	"Add debug info.",
-	"Add dependencies for all targets.",
-	"Override dependencies for all targets.",
-"features",
-"fp-math",
-	"Language version of C3.",
-	"The external libraries to link for all targets.",
-	"The path used to search for external libraries.",
-	"Extra arguments to the linker for all targets.",
-	"Link libc other default libraries (default: yes).",
-	"Set the directory for the MacOS SDK for cross compilation.",
-	"Set the memory environment: normal, small, tiny, none.",
-	"Do not generate (or require) a main function.",
-"opt",
-	"Code optimization level: none, less, more, max.",
-	"Code size optimization: none, small, tiny.",
-	"Output location, relative to project file.",
-	"Override the panic function name.",
-	"Relocation model: none, pic, PIC, pie, PIE.",
-	"Turn safety (contracts, runtime bounds checking, null pointer checks etc) on or off.",
-	"Compile all modules together, enables more inlining.",
-"soft-float",
-	"Sources compiled for all targets.",
-	"Strip unused code and globals from the output. (default: yes)",
-	"Sets the preferred symtab size.",
-	"Use the system linker (default: no for cross compilation, yes otherwise).",
-	"Compile for a particular architecture + OS target.",
-	"Set of targets for the project.",
-	"Override the test function name.",
-"trap-on-wrap",
-	"Use this directory as the C3 standard library path.",
-	"Version using semantic versioning.",
-	"Warnings used for all targets.",
-	"Windows CRT linking: none, static, dynamic (default).",
-	"Set the directory for Windows system library files for cross compilation.",
-	"Set general level of x64 cpu: baseline, ssse3, sse4, avx1, avx2-v1, avx2-v2 (Skylake/Zen1+), avx512 (Icelake/Zen4+), native.",
-	"Set max type of vector use: none, mmx, sse, avx, avx512, native.",
-"x86-stack-struct-return",
-};
-
-const char* project_target_keys[] = {
-	"benchfn",
-	"c-sources-add",
-	"c-sources-override",
-	"cc",
-	"cflags-add",
-	"cflags-override",
-	"cpu",
-	"debug-info",
-	"dependencies-add",
-	"dependencies-override",
-	"dependency-search-paths-add",
-	"dependency-search-paths-override",
-	"features",
-	"fp-math",
-	"langrev",
-	"linked-libraries-add",
-	"linked-libraries-override",
-	"linker-search-paths-add",
-	"linker-search-paths-override",
-	"link-args-add",
-	"link-args-override",
-	"link-libc",
-	"macossdk",
-	"memory-env",
-	"no-entry",
-	"opt",
-	"optlevel",
-	"optsize",
-	"output"
-	"panicfn",
-	"reloc",
-	"safe",
-	"single-module",
-	"soft-float",
-	"sources-add",
-	"sources-override",
-	"strip-unused",
-	"symtab",
-	"system-linker",
-	"target",
-	"testfn",
-	"trap-on-wrap",
-	"type",
-	"use-stdlib",
-	"version",
-	"warnings",
-	"wincrt",
-	"winsdk",
-	"x86cpu",
-	"x86vec",
-	"x86-stack-struct-return",
+const char* project_target_keys[][2] = {
+		{"benchfn", "Override the benchmark function."},
+		{"c-sources-add", "Additional C sources to be compiled for the target."},
+		{"c-sources-override", "C sources to be compiled, overriding global settings."},
+		{"cc", "Set C compiler (defaults to 'cc')."},
+		{"cflags-add", "Additional C compiler flags for the target."},
+		{"cflags-override", "C compiler flags for the target, overriding global settings."},
+		{"cpu", "CPU name, used for optimizations in the compiler backend."},
+		{"debug-info", "Debug level: none, line-tables, full."},
+		{"dependencies-add", "Additional C3 library dependencies for the target."},
+		{"dependencies-override", "C3 library dependencies for this target, overriding global settings."},
+		{"dependency-search-paths-add", "Additional C3 library search paths for the target."},
+		{"dependency-search-paths-override", "C3 library search paths for this target, overriding global settings."},
+		{"exec-add", "Additional scripts to run for the target."},
+		{"exec-override", "Scripts to run for this target, overriding global settings."},
+		{"features", "Features enabled for all targets."},
+		{"fp-math", "Set math behaviour: `strict`, `relaxed` or `fast`."},
+		{"langrev", "Version of the C3 language used."},
+		{"linked-libraries-add", "Additional libraries linked by the linker for the target."},
+		{"linked-libraries-override", "Libraries linked by the linker for this target, overriding global settings."},
+		{"linker-search-paths-add", "Additional linker search paths for the target."},
+		{"linker-search-paths-override", "Linker search paths for this target, overriding global settings."},
+		{"link-args-add", "Additional linker arguments for the target."},
+		{"link-args-override", "Linker arguments for this target, overriding global settings."},
+		{"link-libc", "Link libc (default: true)."},
+		{"macossdk", "Set the directory for the MacOS SDK for cross compilation."},
+		{"memory-env", "Set the memory environment: normal, small, tiny, none."},
+		{"no-entry", "Do not generate (or require) a main function."},
+		{"opt", "Link libc (default: true)."},
+		{"optlevel", "Code optimization level: none, less, more, max."},
+		{"optsize", "Code size optimization: none, small, tiny."},
+		{"output", "Output location, relative to project file."},
+		{"panicfn", "Override the panic function."},
+		{"reloc", "Relocation model: none, pic, PIC, pie, PIE."},
+		{"safe", "Set safety (contracts, runtime bounds checking, null pointer checks etc) on or off."},
+		{"script-dir", "The directory where 'exec' is run."},
+		{"single-module", "Compile all modules together, enables more inlining."},
+		{"soft-float", "Output soft-float functions."},
+		{"sources-add", "Additional paths to project sources for the target."},
+		{"sources-override", "Paths to project sources for this target, overriding global settings."},
+		{"strip-unused", "Strip unused code and globals from the output. (default: true)"},
+		{"symtab", "Sets the preferred symtab size."},
+		{"system-linker", "Use the system linker (default: no for cross compilation, yes otherwise)."},
+		{"target", "Compile for a particular architecture + OS target."},
+		{"testfn", "Override the test function."},
+		{"trap-on-wrap", "Make signed and unsigned integer overflow generate a panic rather than wrapping."},
+		{"type", "Type of output, one of 'executable', 'static-lib', 'dynamic-lib', 'benchmark', 'test', 'object-files'." },
+		{"use-stdlib", "Include the standard library (default: true)."},
+		{"version", "Version using semantic versioning."},
+		{"warnings", "Warnings used for all targets."},
+		{"wincrt", "Windows CRT linking: none, static, dynamic (default)."},
+		{"winsdk", "Set the path to Windows system library files for cross compilation."},
+		{"x86cpu", "Set general level of x64 cpu: baseline, ssse3, sse4, avx1, avx2-v1, avx2-v2 (Skylake/Zen1+), avx512 (Icelake/Zen4+), native."},
+		{"x86vec", "Set max type of vector use: none, mmx, sse, avx, avx512, native."},
+		{"x86-stack-struct-return", "Return structs on the stack for x86."},
 };
 
 const int project_target_keys_count = ELEMENTLEN(project_target_keys);
 
-const char* project_target_descriptions[] = {
-	"Override the benchmark function name.",
-	"Add C sources to be compiled.",
-	"Override C sources to be compiled.",
-	"Specify the C compiler.",
-	"Add flags for the C compiler.",
-	"Override flags for the C compiler.",
-	"CPU name, used for optimizations in the compiler backend.",
-	"Add debug info.",
-	"Add dependencies for this target.",
-	"Override dependencies for this target.",
-	"Add directories where C3 library files may be found",
-	"Override directories where C3 library files may be found",
-"features",
-	"FP math behaviour: strict, relaxed, fast.",
-	"Language version of C3.",
-	"Additional libraries to be linked.",
-	"Override libraries to be linked.",
-	"Add search paths for the linker.",
-	"Override search paths for the linker.",
-	"Add arguments for the linker.",
-	"Override arguments for the linker.",
-	"Link libc other default libraries (default: yes).",
-	"Set the directory for the MacOS SDK for cross compilation.",
-	"Set the memory environment: normal, small, tiny, none.",
-	"Do not generate (or require) a main function.",
-"opt",
-	"Code optimization level: none, less, more, max.",
-	"Code size optimization: none, small, tiny.",
-	"Override the panic function name.",
-	"Relocation model: none, pic, PIC, pie, PIE.",
-	"Turn safety (contracts, runtime bounds checking, null pointer checks etc) on or off.",
-	"Compile all modules together, enables more inlining.",
-"soft-float",
-	"Add sources for the target.",
-	"Override sources for the target.",
-	"Strip unused code and globals from the output. (default: yes)",
-	"Sets the preferred symtab size.",
-	"Use the system linker (default: no for cross compilation, yes otherwise).",
-	"Compile for a particular architecture + OS target.",
-	"Override the test function name.",
-"trap-on-wrap",
-	"Executable or library.",
-	"Use this directory as the C3 standard library path.",
-	"Version using semantic versioning.",
-	"Warnings used for this target.",
-	"Windows CRT linking: none, static, dynamic (default).",
-	"Set the directory for Windows system library files for cross compilation.",
-	"Set general level of x64 cpu: baseline, ssse3, sse4, avx1, avx2-v1, avx2-v2 (Skylake/Zen1+), avx512 (Icelake/Zen4+), native.",
-	"Set max type of vector use: none, mmx, sse, avx, avx512, native.",
-"x86-stack-struct-return",
-};
-
 const char *get_valid_string(JSONObject *table, const char *key, const char *category, bool mandatory)
 {
 	JSONObject *value = json_obj_get(table, key);
@@ -303,7 +208,7 @@ static const char **get_valid_array(JSONObject *table, const char *key, const ch
 	return values;
 }
 
-static void check_json_keys(const char** valid_keys, size_t key_count, JSONObject *json, const char *type)
+static void check_json_keys(const char* valid_keys[][2], size_t key_count, JSONObject *json, const char *type)
 {
 	static bool failed_shown = false;
 	bool failed = false;
@@ -312,7 +217,7 @@ static void check_json_keys(const char** valid_keys, size_t key_count, JSONObjec
 		const char *key = json->keys[i];
 		for (size_t j = 0; j < key_count; j++)
 		{
-			if (strcmp(key, valid_keys[j]) == 0) goto OK;
+			if (strcmp(key, valid_keys[j][0]) == 0) goto OK;
 		}
 		eprintf("WARNING: Unknown parameter '%s' in '%s'.\n", key, type);
 		failed = true;
@@ -360,6 +265,30 @@ static void load_into_build_target(JSONObject *json, const char *type, BuildTarg
 	const char *cc = get_valid_string(json, "cc", type, false);
 	if (cc) target->cc = cc;
 
+	const char *script_dir = get_valid_string(json, "script-dir", type, false);
+	if (script_dir) target->script_dir = script_dir;
+
+	// Exec
+	const char **exec = get_valid_array(json, is_default ? "exec" : "exec-override" , type, false);
+	const char **exec_add = is_default ? NULL : get_valid_array(json, "exec-add" , type, false);
+	if (exec && exec_add)
+	{
+		error_exit("'%s' is combining both 'exec-add' and 'exec-override', only one may be used.", type);
+	}
+	if (exec_add && !target->exec)
+	{
+		target->exec = exec_add;
+		exec_add = NULL;
+	}
+	if (exec) target->exec = exec;
+	if (exec_add)
+	{
+		assert(target->exec);
+		FOREACH_BEGIN(const char *exec_command, exec_add)
+			vec_add(target->exec, exec_command);
+		FOREACH_END();
+	}
+
 	// CFlags
 	const char *cflags = get_valid_string(json, is_default ? "cflags" : "cflags-override" , type, false);
 	const char *cflags_add = is_default ? NULL : get_valid_string(json, "cflags-add" , type, false);
diff --git a/src/build/project_creation.c b/src/build/project_creation.c
index 472655a3d..83c1d30e4 100644
--- a/src/build/project_creation.c
+++ b/src/build/project_creation.c
@@ -202,7 +202,7 @@ void create_library(BuildOptions *build_options)
 	chdir_or_fail(build_options, build_options->project_name);
 	create_file_or_fail(build_options, "LICENSE", NULL);
 	create_file_or_fail(build_options, "README.md", LIB_README, build_options->project_name);
-	mkdir_or_fail(build_options, "run");
+	mkdir_or_fail(build_options, "scripts");
 	scratch_buffer_clear();
 	scratch_buffer_printf("%s.c3i", build_options->project_name);
 	const char *interface_file = scratch_buffer_copy();
@@ -260,7 +260,7 @@ void create_project(BuildOptions *build_options)
 	mkdir_or_fail(build_options, "docs");
 	mkdir_or_fail(build_options, "lib");
 	mkdir_or_fail(build_options, "resources");
-	mkdir_or_fail(build_options, "run");
+	mkdir_or_fail(build_options, "scripts");
 	mkdir_or_fail(build_options, "src");
 	chdir_or_fail(build_options, "src");
 
diff --git a/src/compiler/compiler.c b/src/compiler/compiler.c
index bd40060ba..264af124e 100644
--- a/src/compiler/compiler.c
+++ b/src/compiler/compiler.c
@@ -736,18 +736,16 @@ void print_syntax(BuildOptions *options)
 		int width;
 		puts("Project properties");
 		puts("------------------");
-		width = find_padding_length(project_default_keys, project_default_keys_count);
 		for (int i = 0; i < project_default_keys_count; i++)
 		{
-			printf("%2d %-*s%s\n", i + 1, width, project_default_keys[i], project_default_descriptions[i]);
+			printf("%2d %-*s%s\n", i + 1, 35, project_default_keys[i][0], project_default_keys[i][1]);
 		}
 		puts("");
 		puts("Target properties");
 		puts("-----------------");
-		width = find_padding_length(project_target_keys, project_target_keys_count);
 		for (int i = 0; i < project_target_keys_count; i++)
 		{
-			printf("%2d %-*s%s\n", i + 1, width, project_target_keys[i], project_target_descriptions[i]);
+			printf("%2d %-*s%s\n", i + 1, 35, project_target_keys[i][0], project_target_keys[i][1]);
 		}
 		puts("");
 	}
@@ -827,6 +825,39 @@ static int jump_buffer_size()
 	UNREACHABLE
 }
 
+static void execute_scripts(void)
+{
+	if (!vec_size(active_target.exec)) return;
+	if (active_target.trust_level < TRUST_FULL)
+	{
+		error_exit("This target has 'exec' directives, to run it trust level must be set to '--trust=full'.");
+	}
+	char *old_path = NULL;
+	if (active_target.script_dir)
+	{
+		old_path = getcwd(NULL, 0);
+		if (!dir_change(active_target.script_dir))
+		{
+			free(old_path);
+			error_exit("Failed to open script dir '%s'", active_target.script_dir);
+		}
+	}
+	FOREACH_BEGIN(const char *exec, active_target.exec)
+		StringSlice execs = slice_from_string(exec);
+		StringSlice call = slice_next_token(&execs, ' ');
+		if (call.len < 3 || call.ptr[call.len - 3] != '.' || call.ptr[call.len - 2] != 'c' || call.ptr[call.len - 2] != '3')
+		{
+			(void)execute_cmd(exec);
+			continue;
+		}
+		scratch_buffer_clear();
+		scratch_buffer_append_len(call.ptr, call.len);
+		(void)compile_and_invoke(scratch_buffer_to_string(), execs.len ? execs.ptr : "");
+	FOREACH_END();
+	dir_change(old_path);
+	free(old_path);
+}
+
 void compile()
 {
 	symtab_init(active_target.symtab_size);
@@ -836,6 +867,7 @@ void compile()
 		static const char* c_suffix_list[3] = { ".c" };
 		active_target.csources = target_expand_source_names(active_target.csource_dirs, c_suffix_list, 1, false);
 	}
+	execute_scripts();
 	global_context.main = NULL;
 	global_context.string_type = NULL;
 	asm_target.initialized = false;
@@ -876,6 +908,11 @@ void compile()
 	compiler_init_time = bench_mark();
 
 	if (!vec_size(active_target.sources) && !active_target.read_stdin) error_exit("No files to compile.");
+
+	if (active_target.exec)
+	{
+
+	}
 	if (active_target.lex_only)
 	{
 		compiler_lex();
@@ -1004,15 +1041,24 @@ File *compile_and_invoke(const char *file, const char *args)
 	scratch_buffer_clear();
 	scratch_buffer_append(compiler_path);
 #if (_MSC_VER)
-	const char *output = "__c3_exec.exe";
+	const char *output = "__c3exec__.exe";
 #else
-	const char *output = "__c3_exec";
+	const char *output = "__c3exec__";
 #endif
-	scratch_buffer_printf(" compile %s -o %s", file, output);
+	scratch_buffer_append(" compile");
+	StringSlice slice = slice_from_string(file);
+	while (slice.len > 0)
+	{
+		StringSlice file_name = slice_next_token(&slice, ';');
+		if (!file_name.len) continue;
+		scratch_buffer_append_char(' ');
+		scratch_buffer_append_len(file_name.ptr, file_name.len);
+	}
+	scratch_buffer_printf(" -o %s", output);
 	const char *out;
 	if (!execute_cmd_failable(scratch_buffer_to_string(), &out))
 	{
-		error_exit("Failed to compile script %s.", file);
+		error_exit("Failed to compile script '%s'.", file);
 	}
 	DEBUG_LOG("EXEC OUT: %s", out);
 	scratch_buffer_clear();
@@ -1024,7 +1070,7 @@ File *compile_and_invoke(const char *file, const char *args)
 	scratch_buffer_append(args);
 	if (!execute_cmd_failable(scratch_buffer_to_string(), &out))
 	{
-		error_exit("Error invoking script %s with arguments %s.", file, args);
+		error_exit("Error invoking script '%s' with arguments %s.", file, args);
 	}
 	return source_file_text_load(file, out);
 }
diff --git a/src/compiler/compiler_internal.h b/src/compiler/compiler_internal.h
index efc506ccf..57ba97c33 100644
--- a/src/compiler/compiler_internal.h
+++ b/src/compiler/compiler_internal.h
@@ -45,11 +45,9 @@ typedef uint16_t SectionId;
 #define CLOBBER_FLAG_ELEMENTS 4
 #define MAX_CLOBBER_FLAGS (64 * CLOBBER_FLAG_ELEMENTS)
 
-extern const char *project_default_keys[];
-extern const char *project_default_descriptions[];
+extern const char *project_default_keys[][2];
 extern const int project_default_keys_count;
-extern const char* project_target_keys[];
-extern const char* project_target_descriptions[];
+extern const char* project_target_keys[][2];
 extern const int project_target_keys_count;
 
 typedef struct Ast_ Ast;
diff --git a/src/compiler/sema_passes.c b/src/compiler/sema_passes.c
index 99c71d8fc..9c8b5a6c0 100644
--- a/src/compiler/sema_passes.c
+++ b/src/compiler/sema_passes.c
@@ -163,7 +163,7 @@ static Decl **sema_load_include(CompilationUnit *unit, Decl *decl)
 {
 	if (active_target.trust_level < TRUST_INCLUDE)
 	{
-		SEMA_ERROR(decl, "'$include' not permitted, trust level must be set to '-t2' or '-t3' to permit it.");
+		SEMA_ERROR(decl, "'$include' not permitted, trust level must be set to '--trust=include' or '--trust=full' to permit it.");
 		return NULL;
 	}
 	SemaContext context;
@@ -192,7 +192,7 @@ static Decl **sema_run_exec(CompilationUnit *unit, Decl *decl)
 {
 	if (active_target.trust_level < TRUST_FULL)
 	{
-		SEMA_ERROR(decl, "'$exec' not permitted, trust level must be set to '-t3' to permit it.");
+		SEMA_ERROR(decl, "'$exec' not permitted, trust level must be set to '--trust=full' to permit it.");
 		return NULL;
 	}
 	SemaContext context;
@@ -266,6 +266,18 @@ static Decl **sema_run_exec(CompilationUnit *unit, Decl *decl)
 		UNREACHABLE
 	FOREACH_END();
 	File *file;
+	// TODO fix Win32
+	char *old_path = NULL;
+	if (active_target.script_dir)
+	{
+		old_path = getcwd(NULL, 0);
+		if (!dir_change(active_target.script_dir))
+		{
+			free(old_path);
+			SEMA_ERROR(decl, "Failed to open script dir '%s'", active_target.script_dir);
+			return NULL;
+		}
+	}
 	if (c3_script)
 	{
 		file = compile_and_invoke(file_str, scratch_buffer_copy());
@@ -275,6 +287,16 @@ static Decl **sema_run_exec(CompilationUnit *unit, Decl *decl)
 		const char *output = execute_cmd(scratch_buffer_to_string());
 		file = source_file_text_load(scratch_buffer_to_string(), output);
 	}
+	if (old_path)
+	{
+		success = dir_change(old_path);
+		free(old_path);
+		if (!success)
+		{
+			SEMA_ERROR(decl, "Failed to open run dir '%s'", active_target.script_dir);
+			return NULL;
+		}
+	}
 	if (global_context.includes_used++ > MAX_INCLUDES)
 	{
 		SEMA_ERROR(decl, "This $include would cause the maximum number of includes (%d) to be exceeded.", MAX_INCLUDES);
diff --git a/src/version.h b/src/version.h
index c4937ce25..f8b1b2e32 100644
--- a/src/version.h
+++ b/src/version.h
@@ -1 +1 @@
-#define COMPILER_VERSION "0.4.665"
\ No newline at end of file
+#define COMPILER_VERSION "0.4.666"
\ No newline at end of file