diff --git a/Cargo.lock b/Cargo.lock
index f2d918ec898..8f6b74d3f49 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1242,6 +1242,7 @@ dependencies = [
  "msg",
  "serde",
  "serde_json",
+ "servo_config",
  "servo_rand",
  "servo_url",
  "time",
@@ -5433,6 +5434,7 @@ dependencies = [
  "libloading 0.5.2",
  "libservo",
  "log",
+ "serde_json",
  "servo-media",
  "surfman",
  "webxr",
diff --git a/components/config/opts.rs b/components/config/opts.rs
index 47d92f986d5..c5ca6907bee 100644
--- a/components/config/opts.rs
+++ b/components/config/opts.rs
@@ -112,9 +112,12 @@ pub struct Opts {
     /// remote Firefox debugger connections.
     pub debugger_port: Option<u16>,
 
-    /// `None` to disable devtools or `Some` with a port number to start a server to listen to
-    /// remote Firefox devtools connections.
-    pub devtools_port: Option<u16>,
+    /// Port number to start a server to listen to remote Firefox devtools connections.
+    /// 0 for random port.
+    pub devtools_port: u16,
+
+    /// Start the devtools server at startup
+    pub devtools_server_enabled: bool,
 
     /// `None` to disable WebDriver or `Some` with a port number to start a server to listen to
     /// remote WebDriver commands.
@@ -482,7 +485,8 @@ pub fn default_opts() -> Opts {
         enable_canvas_antialiasing: true,
         trace_layout: false,
         debugger_port: None,
-        devtools_port: None,
+        devtools_port: 0,
+        devtools_server_enabled: false,
         webdriver_port: None,
         initial_window_size: Size2D::new(1024, 740),
         multiprocess: false,
@@ -802,11 +806,22 @@ pub fn from_cmdline_args(mut opts: Options, args: &[String]) -> ArgumentParsingR
             })
         });
 
-    // Set default port 0 for a random port to be selected.
-    let devtools_port = opt_match.opt_default("devtools", "0").map(|port| {
-        port.parse()
-            .unwrap_or_else(|err| args_fail(&format!("Error parsing option: --devtools ({})", err)))
-    });
+    let (devtools_enabled, devtools_port) = if opt_match.opt_present("devtools") {
+        let port = opt_match
+            .opt_str("devtools")
+            .map(|port| {
+                port.parse().unwrap_or_else(|err| {
+                    args_fail(&format!("Error parsing option: --devtools ({})", err))
+                })
+            })
+            .unwrap_or(pref!(devtools.server.port));
+        (true, port as u16)
+    } else {
+        (
+            pref!(devtools.server.enabled),
+            pref!(devtools.server.port) as u16,
+        )
+    };
 
     let webdriver_port = opt_match.opt_default("webdriver", "7000").map(|port| {
         port.parse().unwrap_or_else(|err| {
@@ -874,6 +889,7 @@ pub fn from_cmdline_args(mut opts: Options, args: &[String]) -> ArgumentParsingR
         trace_layout: debug_options.trace_layout,
         debugger_port: debugger_port,
         devtools_port: devtools_port,
+        devtools_server_enabled: devtools_enabled,
         webdriver_port: webdriver_port,
         initial_window_size: initial_window_size,
         multiprocess: opt_match.opt_present("M"),
diff --git a/components/config/prefs.rs b/components/config/prefs.rs
index 5ac6b19d940..1ecc245ff9f 100644
--- a/components/config/prefs.rs
+++ b/components/config/prefs.rs
@@ -123,6 +123,12 @@ mod gen {
                     },
                 },
             },
+            devtools: {
+                server: {
+                    enabled: bool,
+                    port: i64,
+                },
+            },
             dom: {
                 webgpu: {
                     enabled: bool,
diff --git a/components/devtools/Cargo.toml b/components/devtools/Cargo.toml
index 6a6532df54a..68da8489cb7 100644
--- a/components/devtools/Cargo.toml
+++ b/components/devtools/Cargo.toml
@@ -22,6 +22,7 @@ log = "0.4"
 msg = { path = "../msg" }
 serde = "1.0"
 serde_json = "1.0"
+servo_config = { path = "../config" }
 servo_rand = { path = "../rand" }
 servo_url = { path = "../url" }
 time = "0.1"
diff --git a/components/servo/lib.rs b/components/servo/lib.rs
index c6b368d8b2a..9ea3bc71643 100644
--- a/components/servo/lib.rs
+++ b/components/servo/lib.rs
@@ -356,9 +356,15 @@ where
         let mem_profiler_chan = profile_mem::Profiler::create(opts.mem_profiler_period);
 
         let debugger_chan = opts.debugger_port.map(|port| debugger::start_server(port));
-        let devtools_chan = opts
-            .devtools_port
-            .map(|port| devtools::start_server(port, embedder_proxy.clone()));
+
+        let devtools_chan = if opts.devtools_server_enabled {
+            Some(devtools::start_server(
+                opts.devtools_port,
+                embedder_proxy.clone(),
+            ))
+        } else {
+            None
+        };
 
         let coordinates = window.get_coordinates();
         let device_pixel_ratio = coordinates.hidpi_factor.get();
diff --git a/ports/libsimpleservo/api/Cargo.toml b/ports/libsimpleservo/api/Cargo.toml
index 17e914f5468..97e6b5e53ae 100644
--- a/ports/libsimpleservo/api/Cargo.toml
+++ b/ports/libsimpleservo/api/Cargo.toml
@@ -30,6 +30,7 @@ libloading = "0.5"
 
 [build-dependencies]
 gl_generator = "0.14"
+serde_json = "1.0"
 
 [features]
 debugmozjs = ["libservo/debugmozjs"]
diff --git a/ports/libsimpleservo/api/build.rs b/ports/libsimpleservo/api/build.rs
index 243e139cf97..16337042c3c 100644
--- a/ports/libsimpleservo/api/build.rs
+++ b/ports/libsimpleservo/api/build.rs
@@ -3,6 +3,7 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
 use gl_generator::{Api, Fallbacks, Profile, Registry};
+use serde_json::{self, Value};
 use std::env;
 use std::fs::File;
 use std::path::PathBuf;
@@ -40,4 +41,30 @@ fn main() {
             .write_bindings(gl_generator::StructGenerator, &mut file)
             .unwrap();
     }
+
+    // Merge prefs.json and package-prefs.json
+    let mut default_prefs = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
+    default_prefs.push("../../../resources/prefs.json");
+    let mut prefs: Value = serde_json::from_reader(File::open(&default_prefs).unwrap()).unwrap();
+    let mut pkg_prefs = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
+    pkg_prefs.push("../../../resources/package-prefs.json");
+    let pkg_prefs: Value = serde_json::from_reader(File::open(&pkg_prefs).unwrap()).unwrap();
+    if target.contains("uwp") {
+        // Assuming Hololens build
+        let to_merge = pkg_prefs
+            .as_object()
+            .unwrap()
+            .get("hololens")
+            .unwrap()
+            .as_object()
+            .unwrap();
+        for (key, value) in to_merge.iter() {
+            prefs
+                .as_object_mut()
+                .unwrap()
+                .insert(key.clone(), value.clone());
+        }
+    }
+    let file = File::create(&dest.join("prefs.json")).unwrap();
+    serde_json::to_writer(file, &prefs).unwrap();
 }
diff --git a/ports/libsimpleservo/api/src/lib.rs b/ports/libsimpleservo/api/src/lib.rs
index fc9ce60b8f9..d01239a1e75 100644
--- a/ports/libsimpleservo/api/src/lib.rs
+++ b/ports/libsimpleservo/api/src/lib.rs
@@ -30,8 +30,7 @@ use servo::euclid::{Point2D, Rect, Scale, Size2D, Vector2D};
 use servo::keyboard_types::{Key, KeyState, KeyboardEvent};
 use servo::msg::constellation_msg::TraversalDirection;
 use servo::script_traits::{TouchEventType, TouchId};
-use servo::servo_config::opts;
-use servo::servo_config::{pref, set_pref};
+use servo::servo_config::{opts, pref};
 use servo::servo_url::ServoUrl;
 use servo::webrender_api::units::DevicePixel;
 use servo::webrender_api::ScrollLocation;
@@ -62,7 +61,6 @@ pub struct InitOptions {
     pub coordinates: Coordinates,
     pub density: f32,
     pub xr_discovery: Option<webxr::Discovery>,
-    pub enable_subpixel_text_antialiasing: bool,
     pub gl_context_pointer: Option<*const c_void>,
     pub native_display_pointer: Option<*const c_void>,
     pub native_widget: *mut c_void,
@@ -227,22 +225,15 @@ pub fn init(
 ) -> Result<(), &'static str> {
     resources::set(Box::new(ResourceReaderInstance::new()));
 
-    let mut args = mem::replace(&mut init_opts.args, vec![]);
-    if !args.is_empty() {
-        // opts::from_cmdline_args expects the first argument to be the binary name.
-        args.insert(0, "servo".to_string());
-
-        set_pref!(
-            gfx.subpixel_text_antialiasing.enabled,
-            init_opts.enable_subpixel_text_antialiasing
-        );
-        opts::from_cmdline_args(Options::new(), &args);
-    }
-
     if let Some(prefs) = init_opts.prefs {
         add_user_prefs(prefs);
     }
 
+    let mut args = mem::replace(&mut init_opts.args, vec![]);
+    // opts::from_cmdline_args expects the first argument to be the binary name.
+    args.insert(0, "servo".to_string());
+    opts::from_cmdline_args(Options::new(), &args);
+
     let pref_url = ServoUrl::parse(&pref!(shell.homepage)).ok();
     let blank_url = ServoUrl::parse("about:blank").ok();
 
@@ -943,7 +934,7 @@ impl ResourceReaderInstance {
 impl ResourceReaderMethods for ResourceReaderInstance {
     fn read(&self, res: Resource) -> Vec<u8> {
         Vec::from(match res {
-            Resource::Preferences => &include_bytes!("../../../../resources/prefs.json")[..],
+            Resource::Preferences => &include_bytes!(concat!(env!("OUT_DIR"), "/prefs.json"))[..],
             Resource::HstsPreloadList => {
                 &include_bytes!("../../../../resources/hsts_preload.json")[..]
             },
diff --git a/ports/libsimpleservo/capi/src/lib.rs b/ports/libsimpleservo/capi/src/lib.rs
index 01044cf70c2..9bace40a29d 100644
--- a/ports/libsimpleservo/capi/src/lib.rs
+++ b/ports/libsimpleservo/capi/src/lib.rs
@@ -243,7 +243,6 @@ pub struct CInitOptions {
     pub width: i32,
     pub height: i32,
     pub density: f32,
-    pub enable_subpixel_text_antialiasing: bool,
     pub vslogger_mod_list: *const *const c_char,
     pub vslogger_mod_size: u32,
     pub native_widget: *mut c_void,
@@ -446,7 +445,6 @@ unsafe fn init(
         prefs,
         density: opts.density,
         xr_discovery: None,
-        enable_subpixel_text_antialiasing: opts.enable_subpixel_text_antialiasing,
         gl_context_pointer: gl_context,
         native_display_pointer: display,
         native_widget: opts.native_widget,
diff --git a/resources/package-prefs.json b/resources/package-prefs.json
index d419d7e4586..035f08714ee 100644
--- a/resources/package-prefs.json
+++ b/resources/package-prefs.json
@@ -5,6 +5,13 @@
   "linux": {},
   "android": {},
   "windows": {},
+  "hololens": {
+    "_comment": "settings specific to Hololens/UWP builds",
+    "devtools.server.enabled": true,
+    "dom.webxr.enabled": true,
+    "shell.homepage": "https://servo.org/hl-home/",
+    "gfx.subpixel-text-antialiasing.enabled": false
+  },
   "vr": {
     "_comment": "settings specific to VR builds",
     "dom.webvr.enabled": true,
diff --git a/resources/prefs.json b/resources/prefs.json
index d48175de8b4..0cbf5608f90 100644
--- a/resources/prefs.json
+++ b/resources/prefs.json
@@ -1,4 +1,6 @@
 {
+  "devtools.server.enabled": false,
+  "devtools.server.port": 0,
   "dom.bluetooth.enabled": false,
   "dom.bluetooth.testing.enabled": false,
   "dom.canvas_capture.enabled": false,
diff --git a/support/hololens/ServoApp/DefaultUrl.h b/support/hololens/ServoApp/DefaultUrl.h
index b5d82e65478..ba1719dc530 100644
--- a/support/hololens/ServoApp/DefaultUrl.h
+++ b/support/hololens/ServoApp/DefaultUrl.h
@@ -1,8 +1,6 @@
 #pragma once
 
-#define DEFAULT_URL_PROD L"https://servo.org/hl-home/"
-
 // For development purpose.
-// Will override DEFAULT_URL_PROD or any locally stored preferences.
+// Will override shell.homepage preference:
 // #define OVERRIDE_DEFAULT_URL L"data:text/html,<input>"
 // #define OVERRIDE_DEFAULT_URL L"http://localhost:8000/test.html"
diff --git a/support/hololens/ServoApp/ServoControl/Servo.cpp b/support/hololens/ServoApp/ServoControl/Servo.cpp
index 6f724d4bcbb..7adef0a8511 100644
--- a/support/hololens/ServoApp/ServoControl/Servo.cpp
+++ b/support/hololens/ServoApp/ServoControl/Servo.cpp
@@ -147,14 +147,6 @@ Servo::Servo(std::optional<hstring> initUrl, hstring args, GLsizei width,
 
   auto prefs = localSettings.Containers().Lookup(L"servoUserPrefs");
 
-  if (!prefs.Values().HasKey(L"shell.homepage")) {
-    prefs.Values().Insert(L"shell.homepage", box_value(DEFAULT_URL_PROD));
-  }
-
-  if (!prefs.Values().HasKey(L"dom.webxr.enabled")) {
-    prefs.Values().Insert(L"dom.webxr.enabled", box_value(true));
-  }
-
   std::vector<capi::CPref> cprefs;
 
   for (auto pref : prefs.Values()) {
@@ -172,22 +164,9 @@ Servo::Servo(std::optional<hstring> initUrl, hstring args, GLsizei width,
       auto val = unbox_value<bool>(value);
       cpref.value = &val;
     } else if (type == Windows::Foundation::PropertyType::String) {
-      hstring strValue;
-      if (pref.Key() == L"shell.homepage") {
-        if (initUrl.has_value()) {
-          strValue = *initUrl;
-        } else {
-#ifdef OVERRIDE_DEFAULT_URL
-          strValue = OVERRIDE_DEFAULT_URL;
-#else
-          strValue = unbox_value<hstring>(value);
-#endif
-        }
-      } else {
-        strValue = unbox_value<hstring>(value);
-      }
       cpref.pref_type = capi::CPrefType::Str;
-      cpref.value = *hstring2char(strValue);
+      auto val = unbox_value<hstring>(value);
+      cpref.value = *hstring2char(val);
     } else if (type == Windows::Foundation::PropertyType::Int64) {
       cpref.pref_type = capi::CPrefType::Int;
       auto val = unbox_value<int64_t>(value);
@@ -205,15 +184,22 @@ Servo::Servo(std::optional<hstring> initUrl, hstring args, GLsizei width,
     cprefs.push_back(cpref);
   }
 
+  if (initUrl.has_value()) {
+    setNonPersistentHomepage(*initUrl, cprefs);
+  } else {
+#ifdef OVERRIDE_DEFAULT_URL
+    setNonPersistentHomepage(OVERRIDE_DEFAULT_URL, cprefs);
+#endif
+  }
+
   capi::CPrefList prefsList = {cprefs.size(), cprefs.data()};
 
   capi::CInitOptions o;
   o.prefs = &prefsList;
-  o.args = *hstring2char(args + L" --devtools");
+  o.args = *hstring2char(args);
   o.width = mWindowWidth;
   o.height = mWindowHeight;
   o.density = dpi;
-  o.enable_subpixel_text_antialiasing = false;
   o.native_widget = eglNativeWindow;
 
   // Note about logs:
@@ -385,6 +371,20 @@ std::vector<Servo::PrefTuple> Servo::GetPrefs() {
   return vec;
 }
 
+void setNonPersistentHomepage(hstring url, std::vector<capi::CPref> &cprefs) {
+  for (auto cpref : cprefs) {
+    if (strcmp(cpref.key, "shell.homepage") == 0) {
+      cpref.value = *hstring2char(url);
+      return;
+    }
+  }
+  capi::CPref cpref;
+  cpref.key = "shell.homepage";
+  cpref.pref_type = capi::CPrefType::Str;
+  cpref.value = *hstring2char(url);
+  cprefs.push_back(cpref);
+}
+
 winrt::hstring char2hstring(const char *c_str) {
   // FIXME: any better way of doing this?
   auto str = std::string(c_str);
diff --git a/support/hololens/ServoApp/ServoControl/Servo.h b/support/hololens/ServoApp/ServoControl/Servo.h
index 2d8e3b0f091..e6eaf428be1 100644
--- a/support/hololens/ServoApp/ServoControl/Servo.h
+++ b/support/hololens/ServoApp/ServoControl/Servo.h
@@ -21,6 +21,7 @@ using namespace capi;
 
 hstring char2hstring(const char *);
 std::unique_ptr<char *> hstring2char(hstring);
+void setNonPersistentHomepage(hstring, std::vector<capi::CPref> &);
 
 class ServoDelegate;
 
diff --git a/support/hololens/ServoApp/ServoControl/ServoControl.cpp b/support/hololens/ServoApp/ServoControl/ServoControl.cpp
index db4710f0606..d0d1e814e91 100644
--- a/support/hololens/ServoApp/ServoControl/ServoControl.cpp
+++ b/support/hololens/ServoApp/ServoControl/ServoControl.cpp
@@ -661,6 +661,8 @@ void ServoControl::OnServoDevtoolsStarted(bool success, const unsigned int port,
                                           hstring token) {
   RunOnUIThread([=] {
     auto status = success ? DevtoolsStatus::Running : DevtoolsStatus::Failed;
+    // This port works, let's save it for future use.
+    Servo::SetIntPref(L"devtools.server.port", port);
     mOnDevtoolsStatusChangedEvent(status, port, token);
   });
 }