diff --git a/cmd/tools/vast/vast.v b/cmd/tools/vast/vast.v
index faa7e138d8..0917cc5a0d 100644
--- a/cmd/tools/vast/vast.v
+++ b/cmd/tools/vast/vast.v
@@ -1166,6 +1166,9 @@ fn (t Tree) expr(expr ast.Expr) &Node {
 		ast.GoExpr {
 			return t.go_expr(expr)
 		}
+		ast.SpawnExpr {
+			return t.spawn_expr(expr)
+		}
 		ast.OffsetOf {
 			return t.offset_of(expr)
 		}
@@ -1862,6 +1865,15 @@ fn (t Tree) go_expr(expr ast.GoExpr) &Node {
 	return obj
 }
 
+fn (t Tree) spawn_expr(expr ast.SpawnExpr) &Node {
+	mut obj := new_object()
+	obj.add_terse('ast_type', t.string_node('SpawnExpr'))
+	obj.add_terse('call_expr', t.call_expr(expr.call_expr))
+	obj.add_terse('is_expr', t.bool_node(expr.is_expr))
+	obj.add('pos', t.pos(expr.pos))
+	return obj
+}
+
 fn (t Tree) offset_of(expr ast.OffsetOf) &Node {
 	mut obj := new_object()
 	obj.add_terse('ast_type', t.string_node('OffsetOf'))
diff --git a/thirdparty/photon/photonwrapper.h b/thirdparty/photon/photonwrapper.h
new file mode 100644
index 0000000000..f3241a0073
--- /dev/null
+++ b/thirdparty/photon/photonwrapper.h
@@ -0,0 +1,44 @@
+
+
+
+#ifndef C_PHOTONWRAPPER_H_
+#define C_PHOTONWRAPPER_H_
+
+
+#ifdef __cplusplus
+
+#include <fcntl.h>
+//#include <vector>
+
+#include <photon/thread/std-compat.h>
+#include <photon/common/alog.h>
+#include <photon/common/iovector.h>
+#include <photon/fs/localfs.h>
+#include <photon/net/socket.h>
+
+#include <iostream>
+
+extern "C" {
+#else
+    typedef struct CppClass CppClass;
+#endif
+
+//CppClass *cpp_class_create();
+//void cpp_class_destroy(CppClass *c);
+//void cpp_class_do_work(CppClass *c);
+
+int photon_init_default();
+void photon_thread_create11(void* (* f)(void*));
+
+void photon_sleep_s(int n);
+
+void photon_sleep_ms(int n);
+
+
+
+#ifdef __cplusplus
+}
+#endif
+
+
+#endif
diff --git a/vlib/coroutines/coroutines.v b/vlib/coroutines/coroutines.v
new file mode 100644
index 0000000000..a217b2b29c
--- /dev/null
+++ b/vlib/coroutines/coroutines.v
@@ -0,0 +1,21 @@
+// Copyright (c) 2019-2023 Alexander Medvednikov. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+module coroutines
+
+import time
+
+#flag -I @VEXEROOT/thirdparty/photon
+#flag @VEXEROOT/thirdparty/photon/photonwrapper.so
+
+#include "photonwrapper.h"
+
+fn C.photon_init_default() int
+fn C.photon_thread_create11(f voidptr)
+fn C.photon_sleep_s(n int)
+fn C.photon_sleep_ms(n int)
+
+// sleep is coroutine-safe version of time.sleep()
+pub fn sleep(duration time.Duration) {
+	C.photon_sleep_ms(duration.milliseconds())
+}
diff --git a/vlib/v/ast/ast.v b/vlib/v/ast/ast.v
index f4491cdd4a..bd4c387b5b 100644
--- a/vlib/v/ast/ast.v
+++ b/vlib/v/ast/ast.v
@@ -54,6 +54,7 @@ pub type Expr = AnonFn
 	| SelectExpr
 	| SelectorExpr
 	| SizeOf
+	| SpawnExpr
 	| SqlExpr
 	| StringInterLiteral
 	| StringLiteral
@@ -1386,6 +1387,15 @@ pub mut:
 	is_expr   bool
 }
 
+[minify]
+pub struct SpawnExpr {
+pub:
+	pos token.Pos
+pub mut:
+	call_expr CallExpr
+	is_expr   bool
+}
+
 pub struct GotoLabel {
 pub:
 	name string
@@ -1948,10 +1958,11 @@ pub fn (expr Expr) pos() token.Pos {
 		}
 		NodeError, ArrayDecompose, ArrayInit, AsCast, Assoc, AtExpr, BoolLiteral, CallExpr,
 		CastExpr, ChanInit, CharLiteral, ConcatExpr, Comment, ComptimeCall, ComptimeSelector,
-		EnumVal, DumpExpr, FloatLiteral, GoExpr, Ident, IfExpr, IntegerLiteral, IsRefType, Likely,
-		LockExpr, MapInit, MatchExpr, None, OffsetOf, OrExpr, ParExpr, PostfixExpr, PrefixExpr,
-		RangeExpr, SelectExpr, SelectorExpr, SizeOf, SqlExpr, StringInterLiteral, StringLiteral,
-		StructInit, TypeNode, TypeOf, UnsafeExpr, ComptimeType, Nil {
+		EnumVal, DumpExpr, FloatLiteral, GoExpr, SpawnExpr, Ident, IfExpr, IntegerLiteral,
+		IsRefType, Likely, LockExpr, MapInit, MatchExpr, None, OffsetOf, OrExpr, ParExpr,
+		PostfixExpr, PrefixExpr, RangeExpr, SelectExpr, SelectorExpr, SizeOf, SqlExpr,
+		StringInterLiteral, StringLiteral, StructInit, TypeNode, TypeOf, UnsafeExpr, ComptimeType,
+		Nil {
 			return expr.pos
 		}
 		IndexExpr {
diff --git a/vlib/v/ast/str.v b/vlib/v/ast/str.v
index 32d9621dca..39f48da004 100644
--- a/vlib/v/ast/str.v
+++ b/vlib/v/ast/str.v
@@ -403,6 +403,9 @@ pub fn (x Expr) str() string {
 		GoExpr {
 			return 'go ${x.call_expr}'
 		}
+		SpawnExpr {
+			return 'spawn ${x.call_expr}'
+		}
 		Ident {
 			return x.name.clone()
 		}
diff --git a/vlib/v/checker/checker.v b/vlib/v/checker/checker.v
index fbf1aa9347..41261e5156 100644
--- a/vlib/v/checker/checker.v
+++ b/vlib/v/checker/checker.v
@@ -2548,6 +2548,9 @@ pub fn (mut c Checker) expr(node_ ast.Expr) ast.Type {
 		ast.GoExpr {
 			return c.go_expr(mut node)
 		}
+		ast.SpawnExpr {
+			return c.spawn_expr(mut node)
+		}
 		ast.Ident {
 			return c.ident(mut node)
 		}
diff --git a/vlib/v/checker/fn.v b/vlib/v/checker/fn.v
index 99a6ed5eca..c479bf0362 100644
--- a/vlib/v/checker/fn.v
+++ b/vlib/v/checker/fn.v
@@ -2100,7 +2100,7 @@ fn (mut c Checker) method_call(mut node ast.CallExpr) ast.Type {
 	return ast.void_type
 }
 
-fn (mut c Checker) go_expr(mut node ast.GoExpr) ast.Type {
+fn (mut c Checker) spawn_expr(mut node ast.SpawnExpr) ast.Type {
 	ret_type := c.call_expr(mut node.call_expr)
 	if node.call_expr.or_block.kind != .absent {
 		c.error('option handling cannot be done in `spawn` call. Do it when calling `.wait()`',
@@ -2126,6 +2126,33 @@ fn (mut c Checker) go_expr(mut node ast.GoExpr) ast.Type {
 	}
 }
 
+fn (mut c Checker) go_expr(mut node ast.GoExpr) ast.Type {
+	// TODO copypasta from spawn_expr
+	ret_type := c.call_expr(mut node.call_expr)
+	if node.call_expr.or_block.kind != .absent {
+		c.error('option handling cannot be done in `go` call. Do it when calling `.wait()`',
+			node.call_expr.or_block.pos)
+	}
+	// Make sure there are no mutable arguments
+	for arg in node.call_expr.args {
+		if arg.is_mut && !arg.typ.is_ptr() {
+			c.error('function in `go` statement cannot contain mutable non-reference arguments',
+				arg.expr.pos())
+		}
+	}
+	if node.call_expr.is_method && node.call_expr.receiver_type.is_ptr()
+		&& !node.call_expr.left_type.is_ptr() {
+		c.error('method in `go` statement cannot have non-reference mutable receiver',
+			node.call_expr.left.pos())
+	}
+
+	if c.pref.backend.is_js() {
+		return c.table.find_or_register_promise(c.unwrap_generic(ret_type))
+	} else {
+		return c.table.find_or_register_thread(c.unwrap_generic(ret_type))
+	}
+}
+
 fn (mut c Checker) set_node_expected_arg_types(mut node ast.CallExpr, func &ast.Fn) {
 	if node.expected_arg_types.len == 0 {
 		start_idx := if func.is_method { 1 } else { 0 }
diff --git a/vlib/v/eval/expr.v b/vlib/v/eval/expr.v
index fde1fe2604..76796e46c7 100644
--- a/vlib/v/eval/expr.v
+++ b/vlib/v/eval/expr.v
@@ -534,10 +534,10 @@ pub fn (mut e Eval) expr(expr ast.Expr, expecting ast.Type) Object {
 		}
 		ast.AnonFn, ast.ArrayDecompose, ast.AsCast, ast.Assoc, ast.AtExpr, ast.CTempVar,
 		ast.ChanInit, ast.Comment, ast.ComptimeCall, ast.ComptimeSelector, ast.ComptimeType,
-		ast.ConcatExpr, ast.DumpExpr, ast.EmptyExpr, ast.EnumVal, ast.GoExpr, ast.IfGuardExpr,
-		ast.IndexExpr, ast.IsRefType, ast.Likely, ast.LockExpr, ast.MapInit, ast.MatchExpr,
-		ast.Nil, ast.NodeError, ast.None, ast.OffsetOf, ast.OrExpr, ast.RangeExpr, ast.SelectExpr,
-		ast.SqlExpr, ast.TypeNode, ast.TypeOf {
+		ast.ConcatExpr, ast.DumpExpr, ast.EmptyExpr, ast.EnumVal, ast.GoExpr, ast.SpawnExpr,
+		ast.IfGuardExpr, ast.IndexExpr, ast.IsRefType, ast.Likely, ast.LockExpr, ast.MapInit,
+		ast.MatchExpr, ast.Nil, ast.NodeError, ast.None, ast.OffsetOf, ast.OrExpr, ast.RangeExpr,
+		ast.SelectExpr, ast.SqlExpr, ast.TypeNode, ast.TypeOf {
 			e.error('unhandled expression ${typeof(expr).name}')
 		}
 	}
diff --git a/vlib/v/fmt/fmt.v b/vlib/v/fmt/fmt.v
index 78a412cff7..9f89efe464 100644
--- a/vlib/v/fmt/fmt.v
+++ b/vlib/v/fmt/fmt.v
@@ -640,6 +640,9 @@ pub fn (mut f Fmt) expr(node_ ast.Expr) {
 		ast.GoExpr {
 			f.go_expr(node)
 		}
+		ast.SpawnExpr {
+			f.spawn_expr(node)
+		}
 		ast.Ident {
 			f.ident(node)
 		}
@@ -1206,11 +1209,16 @@ pub fn (mut f Fmt) global_decl(node ast.GlobalDecl) {
 	}
 }
 
-pub fn (mut f Fmt) go_expr(node ast.GoExpr) {
+pub fn (mut f Fmt) spawn_expr(node ast.SpawnExpr) {
 	f.write('spawn ')
 	f.call_expr(node.call_expr)
 }
 
+pub fn (mut f Fmt) go_expr(node ast.GoExpr) {
+	f.write('go ')
+	f.call_expr(node.call_expr)
+}
+
 pub fn (mut f Fmt) goto_label(node ast.GotoLabel) {
 	f.writeln('${node.name}:')
 }
diff --git a/vlib/v/gen/c/cgen.v b/vlib/v/gen/c/cgen.v
index ab23af6447..441872904c 100644
--- a/vlib/v/gen/c/cgen.v
+++ b/vlib/v/gen/c/cgen.v
@@ -3160,6 +3160,9 @@ fn (mut g Gen) expr(node_ ast.Expr) {
 				g.write(node.val)
 			}
 		}
+		ast.SpawnExpr {
+			g.spawn_expr(node)
+		}
 		ast.GoExpr {
 			g.go_expr(node)
 		}
@@ -3260,7 +3263,7 @@ fn (mut g Gen) expr(node_ ast.Expr) {
 				mut expr_str := ''
 				if mut node.expr is ast.ComptimeSelector
 					&& (node.expr as ast.ComptimeSelector).left is ast.Ident {
-					// val.$(field.name)?					
+					// val.$(field.name)?
 					expr_str = '${node.expr.left.str()}.${g.comptime_for_field_value.name}'
 				} else if mut node.expr is ast.Ident && g.is_comptime_var(node.expr) {
 					// val?
diff --git a/vlib/v/gen/c/fn.v b/vlib/v/gen/c/fn.v
index 58a726a5ee..d482ff283d 100644
--- a/vlib/v/gen/c/fn.v
+++ b/vlib/v/gen/c/fn.v
@@ -2090,6 +2090,11 @@ fn (mut g Gen) call_args(node ast.CallExpr) {
 }
 
 fn (mut g Gen) go_expr(node ast.GoExpr) {
+	g.writeln('/*go (coroutine) */')
+}
+
+fn (mut g Gen) spawn_expr(node ast.SpawnExpr) {
+	g.writeln('/*spawn (thread) */')
 	line := g.go_before_stmt(0)
 	mut handle := ''
 	tmp := g.new_tmp_var()
diff --git a/vlib/v/gen/js/js.v b/vlib/v/gen/js/js.v
index 491a84bd93..6656dd64f2 100644
--- a/vlib/v/gen/js/js.v
+++ b/vlib/v/gen/js/js.v
@@ -935,6 +935,9 @@ fn (mut g JsGen) expr(node_ ast.Expr) {
 		ast.GoExpr {
 			g.gen_go_expr(node)
 		}
+		ast.SpawnExpr {
+			g.gen_spawn_expr(node)
+		}
 		ast.Ident {
 			g.gen_ident(node)
 		}
@@ -1826,6 +1829,20 @@ fn (mut g JsGen) gen_go_expr(node ast.GoExpr) {
 	g.writeln('})});')
 }
 
+fn (mut g JsGen) gen_spawn_expr(node ast.SpawnExpr) {
+	if g.pref.output_es5 {
+		verror('No support for goroutines on ES5 output')
+		return
+	}
+	g.writeln('new _v_Promise({promise: new Promise(function(resolve){')
+	g.inc_indent()
+	g.write('resolve(')
+	g.expr(node.call_expr)
+	g.write(');')
+	g.dec_indent()
+	g.writeln('})});')
+}
+
 fn (mut g JsGen) gen_import_stmt(it ast.Import) {
 	g.ns.imports[it.mod] = it.alias
 }
diff --git a/vlib/v/markused/walker.v b/vlib/v/markused/walker.v
index 22363bccb2..672cdf77b2 100644
--- a/vlib/v/markused/walker.v
+++ b/vlib/v/markused/walker.v
@@ -273,7 +273,7 @@ fn (mut w Walker) expr(node_ ast.Expr) {
 			w.fn_by_name('eprint')
 			w.fn_by_name('eprintln')
 		}
-		ast.GoExpr {
+		ast.SpawnExpr {
 			w.expr(node.call_expr)
 			if w.pref.os == .windows {
 				w.fn_by_name('panic_lasterr')
@@ -283,6 +283,9 @@ fn (mut w Walker) expr(node_ ast.Expr) {
 				w.fn_by_name('panic_error_number')
 			}
 		}
+		ast.GoExpr {
+			w.expr(node.call_expr)
+		}
 		ast.IndexExpr {
 			w.expr(node.left)
 			w.expr(node.index)
diff --git a/vlib/v/parser/expr.v b/vlib/v/parser/expr.v
index 51f906bc4d..0238d53a53 100644
--- a/vlib/v/parser/expr.v
+++ b/vlib/v/parser/expr.v
@@ -112,9 +112,15 @@ fn (mut p Parser) check_expr(precedence int) !ast.Expr {
 			}
 		}
 		.key_go, .key_spawn {
-			mut go_expr := p.go_expr()
-			go_expr.is_expr = true
-			node = go_expr
+			if p.pref.use_coroutines && p.tok.kind == .key_go {
+				mut go_expr := p.go_expr()
+				go_expr.is_expr = true
+				node = go_expr
+			} else {
+				mut spawn_expr := p.spawn_expr()
+				spawn_expr.is_expr = true
+				node = spawn_expr
+			}
 		}
 		.key_true, .key_false {
 			node = ast.BoolLiteral{
diff --git a/vlib/v/parser/fn.v b/vlib/v/parser/fn.v
index 99397bd0f0..04b61f5d7c 100644
--- a/vlib/v/parser/fn.v
+++ b/vlib/v/parser/fn.v
@@ -1038,7 +1038,7 @@ fn (mut p Parser) fn_args() ([]ast.Param, bool, bool) {
 	return args, types_only, is_variadic
 }
 
-fn (mut p Parser) go_expr() ast.GoExpr {
+fn (mut p Parser) spawn_expr() ast.SpawnExpr {
 	p.next()
 	spos := p.tok.pos()
 	expr := p.expr(0)
@@ -1053,6 +1053,27 @@ fn (mut p Parser) go_expr() ast.GoExpr {
 	pos := spos.extend(p.prev_tok.pos())
 	p.register_auto_import('sync.threads')
 	p.table.gostmts++
+	return ast.SpawnExpr{
+		call_expr: call_expr
+		pos: pos
+	}
+}
+
+fn (mut p Parser) go_expr() ast.GoExpr {
+	p.next()
+	spos := p.tok.pos()
+	expr := p.expr(0)
+	call_expr := if expr is ast.CallExpr {
+		expr
+	} else {
+		p.error_with_pos('expression in `go` must be a function call', expr.pos())
+		ast.CallExpr{
+			scope: p.scope
+		}
+	}
+	pos := spos.extend(p.prev_tok.pos())
+	// p.register_auto_import('coroutines')
+	p.table.gostmts++
 	return ast.GoExpr{
 		call_expr: call_expr
 		pos: pos
diff --git a/vlib/v/parser/parser.v b/vlib/v/parser/parser.v
index 29b4d844ec..25520c0c0d 100644
--- a/vlib/v/parser/parser.v
+++ b/vlib/v/parser/parser.v
@@ -1078,10 +1078,18 @@ fn (mut p Parser) stmt(is_top_level bool) ast.Stmt {
 			}
 		}
 		.key_go, .key_spawn {
-			go_expr := p.go_expr()
-			return ast.ExprStmt{
-				expr: go_expr
-				pos: go_expr.pos
+			if p.pref.use_coroutines && p.tok.kind == .key_go {
+				go_expr := p.go_expr()
+				return ast.ExprStmt{
+					expr: go_expr
+					pos: go_expr.pos
+				}
+			} else {
+				spawn_expr := p.spawn_expr()
+				return ast.ExprStmt{
+					expr: spawn_expr
+					pos: spawn_expr.pos
+				}
 			}
 		}
 		.key_goto {
diff --git a/vlib/v/pref/default.v b/vlib/v/pref/default.v
index a68561e417..6707d37212 100644
--- a/vlib/v/pref/default.v
+++ b/vlib/v/pref/default.v
@@ -218,10 +218,6 @@ pub fn default_tcc_compiler() string {
 }
 
 pub fn (mut p Preferences) default_c_compiler() {
-	// fast_clang := '/usr/local/Cellar/llvm/8.0.0/bin/clang'
-	// if os.exists(fast_clang) {
-	// return fast_clang
-	// }
 	// TODO fix $if after 'string'
 	$if windows {
 		p.ccompiler = 'gcc'
diff --git a/vlib/v/pref/pref.v b/vlib/v/pref/pref.v
index 19c1aab834..45de296f33 100644
--- a/vlib/v/pref/pref.v
+++ b/vlib/v/pref/pref.v
@@ -223,6 +223,7 @@ pub mut:
 	assert_failure_mode AssertFailureMode     // whether to call abort() or print_backtrace() after an assertion failure
 	message_limit       int = 150 // the maximum amount of warnings/errors/notices that will be accumulated
 	nofloat             bool // for low level code, like kernels: replaces f32 with u32 and f64 with u64
+	use_coroutines      bool // experimental coroutines
 	// checker settings:
 	checker_match_exhaustive_cutoff_limit int = 12
 	thread_stack_size                     int = 8388608 // Change with `-thread-stack-size 4194304`. Note: on macos it was 524288, which is too small for more complex programs with many nested callexprs.
@@ -798,6 +799,9 @@ pub fn parse_args_and_show_errors(known_external_commands []string, args []strin
 				res.cmain = cmdline.option(current_args, '-cmain', '')
 				i++
 			}
+			'-use-coroutines' {
+				res.use_coroutines = true
+			}
 			else {
 				if command == 'build' && is_source_file(arg) {
 					eprintln('Use `v ${arg}` instead.')