--- a/src/app.rs
+++ b/src/app.rs
@@ -982,0 +983,5 @@
+    /// Keep the native loop alive when the last window closes (for tray apps).
+    pub fn set_quit_on_last_window_close(&self, quit: bool) {
+        self.platform.set_quit_on_last_window_close(quit);
+    }
+
--- a/src/platform/linux/platform.rs
+++ b/src/platform/linux/platform.rs
@@ -96,0 +97 @@
+    pub quit_on_last_window_close: bool,
@@ -122,0 +124 @@
+            quit_on_last_window_close: true,
@@ -232,0 +235,4 @@
+    }
+
+    fn set_quit_on_last_window_close(&self, quit: bool) {
+        self.with_common(|common| common.quit_on_last_window_close = quit);
--- a/src/platform/linux/wayland/client.rs
+++ b/src/platform/linux/wayland/client.rs
@@ -387 +387 @@
-        if state.windows.is_empty() {
+        if state.windows.is_empty() && state.common.quit_on_last_window_close {
--- a/src/platform/linux/x11/client.rs
+++ b/src/platform/linux/x11/client.rs
@@ -250 +250 @@
-        if state.windows.is_empty() {
+        if state.windows.is_empty() && state.common.quit_on_last_window_close {
--- a/src/platform/windows/platform.rs
+++ b/src/platform/windows/platform.rs
@@ -2 +2 @@
-    cell::RefCell,
+    cell::{Cell, RefCell},
@@ -45,0 +46 @@
+    quit_on_last_window_close: Cell<bool>,
@@ -369,0 +371,4 @@
+    fn set_quit_on_last_window_close(&self, quit: bool) {
+        self.inner.quit_on_last_window_close.set(quit);
+    }
+
@@ -682,0 +688 @@
+            quit_on_last_window_close: Cell::new(true),
@@ -744 +750 @@
-        lock.is_empty()
+        lock.is_empty() && self.quit_on_last_window_close.get()
--- a/src/platform.rs
+++ b/src/platform.rs
@@ -171,0 +172 @@
+    fn set_quit_on_last_window_close(&self, _quit: bool) {}
--- a/src/taffy.rs
+++ b/src/taffy.rs
@@ -312 +312 @@
-            unit.map(|count| vec![repeat(count, vec![minmax(length(0.0), fr(1.0))])])
+            unit.map(|count| vec![repeat(count, vec![minmax(length(0.0_f32), fr(1.0_f32))])])