blog: December in Servo (2025) (#288)

* blog: December in Servo (2025)

* Fix commit list

* Triage 90 commits

* Triage 32 commits

* Triage 31 commits

* Triage 30 commits

* Triage 25 commits

* Triage 26 commits

* Boilerplate post

* Write about multiple windows

* Write about servoshell and API changes

* Write about more API changes (and triage 2 commits)

* Write about devtools

* Add devtools figure

* Issue correction for previous monthly update

* Write about SubtleCrypto

* Reword lede

* Write about rendering bugs

* Write about web platform

* Triage 28 commits

* Triage 27 commits

* Write about DOM changes

* Write about crashes (and a bit about layout)

* Write about garbage collection bugs

* Write about perf changes

* Add multiple windows figure

* Trim figure a bit

* Write about donations

* Write about conference talks and blogs

* Add mention to multiple windows patches

* Add note about servoshell bug on macOS

Author: delan

README.md

@@ -436,3 +436,4 @@ When we make mistakes, we issue corrections on the blog and on social media.
 
 - [**November 2023**](https://servo.org/blog/2023/11/30/embedding-floats-color-mix/) — [An earlier version](https://github.com/servo/servo.org/pull/126) of this post said that Servo now supports the :has() selector, but this was incorrect. While some of the code implementing the feature has landed, it is [not yet enabled](https://github.com/servo/servo/blob/7bcb25c85c98c367c6423ebc0fed964dd08cad56/components/selectors/parser.rs#L276-L279).
 - [**March 2024**](https://servo.org/blog/2024/03/12/sponsoring-servo/) — [An earlier version](https://github.com/servo/servo.org/pull/139) of this post said that over 94% of amounts donated to Servo go directly to the project, with only 6% in fees, but this was incorrect. The actual fees depend on the payment method and the amount you donate, but in most cases they are between 10% and 20%. We are still working on clarifying the exact rules about fees with our crowdfunding platforms, so check our [Sponsorship](https://servo.org/sponsorship/) page for the latest information.
+- [**November 2025**](https://servo.org/blog/2025/12/15/november-in-servo/) — [An earlier version](https://github.com/servo/servo.org/pull/282) of this post said that Servo now has full support for ChaCha20-Poly1305, but this was incorrect. We had only landed the ‘importKey’ and ‘exportKey’ operations. The ‘encrypt’, ‘decrypt’, and ‘generateKey’ options landed in the following month.

_posts/2025-12-15-november-in-servo.md

@@ -7,6 +7,13 @@ summary:    All of these updates are in Servo 0.0.3.
 categories:
 ---
 
+<aside class="_correction">
+
+**Correction (2026-01-19)**
+
+[An earlier version](https://github.com/servo/servo.org/pull/282) of this post said that Servo now has full support for ChaCha20-Poly1305, but this was incorrect. We had only landed the ‘importKey’ and ‘exportKey’ operations. The ‘encrypt’, ‘decrypt’, and ‘generateKey’ options landed in the following month.
+</aside>
+
 Landing in [**Servo 0.0.3**](https://github.com/servo/servo/releases/tag/v0.0.3) and our November nightly builds, we now have **context menus** for links, images, and other web content ([@atbrakhi](https://github.com/atbrakhi), [@mrobinson](https://github.com/mrobinson), [#40434](https://github.com/servo/servo/pull/40434), [#40501](https://github.com/servo/servo/pull/40501)), **vsync on Android** ([@mrobinson](https://github.com/mrobinson), [#40306](https://github.com/servo/servo/pull/40306)), **light mode** for the **new tab page** ([@arihant2math](https://github.com/arihant2math), [#40272](https://github.com/servo/servo/pull/40272)), plus several web platform features:
 
 - **&lt;video controls>** ([@rayguo17](https://github.com/rayguo17), [#40578](https://github.com/servo/servo/pull/40578))

_posts/2026-01-19-december-in-servo.md

@@ -0,0 +1,188 @@
+---
+layout:     post
+tags:       blog
+title:      "December in Servo: and more!"
+date:       2026-01-19
+summary:    ao!! wrrrrao!!
+categories:
+---
+
+<!--
+- 2991.40/month opencollective
+- 3830.00/month github
+- 288.75/month 30 donors thanks.dev
+-->
+
+**Servo 0.0.4** and our December nightly builds now support **multiple windows** (@mrobinson, @mukilan, #40927, #41235, #41144)!
+This builds on features that landed in Servo’s embedding API [last month]({{ '/blog/2025/12/15/november-in-servo/' | url }}).
+We’ve also landed support for several web platform features, both old and new:
+
+- **‘contrast-color()’** in CSS color values (@webbeef, #41542)
+- partial support for **&lt;meta charset>** (@simonwuelker, #41376)
+- partial support for [**encoding sniffing**](https://html.spec.whatwg.org/multipage/#encoding-sniffing-algorithm) (@simonwuelker, #41435)
+- **‘background’** and **‘bgcolor’** attributes on &lt;table>, &lt;thead>, &lt;tbody>, &lt;tfoot>, &lt;tr>, &lt;td>, &lt;th> (@simonwuelker, #41272)
+- **tee()** on **readable byte streams** (@Taym95, #35991)
+
+<aside class="_note">
+
+**Note:** due to [a known issue](https://github.com/servo/servo/issues/42069), servoshell on macOS may not be able to directly open new windows, depending on your system settings.
+</aside>
+
+<figure>
+    <img src="{{ '/img/blog/2026-01-diffie.png' | url }}" alt="Servo 0.0.4 showing new support for multiple windows">
+</figure>
+
+For better compatibility with older web content, we now support **vendor-prefixed** CSS properties like ‘-moz-transform’ (@mrobinson, #41350), as well as window.**clientInformation** (@Taym95, #41111).
+
+We’ve continued shipping the **[SubtleCrypto](https://w3c.github.io/webcrypto/) [API](https://wicg.github.io/webcrypto-modern-algos/)**, with full support for **ChaCha20-Poly1305**, **RSA-OAEP**, **RSA-PSS**, and **RSASSA-PKCS1-v1_5** (see below), plus **importKey() for ML-KEM** (@kkoyung, #41585) and several other improvements (@kkoyung, @PaulTreitel, @danilopedraza, #41180, #41395, #41428, #41442, #41472, #41544, #41563, #41587, #41039, #41292):
+
+<figure style="overflow-x: scroll;">
+
+| Algorithm | |
+|---|---|
+| <span style=white-space:nowrap>ChaCha20-Poly1305</span> | (@kkoyung, #40978, #41003, #41030) |
+| <span style=white-space:nowrap>RSA-OAEP</span> | (@kkoyung, @TimvdLippe, @jdm, #41225, #41217, #41240, #41316) |
+| <span style=white-space:nowrap>RSA-PSS</span> | (@kkoyung, @jdm, #41157, #41225, #41240, #41287) |
+| <span style=white-space:nowrap>RSASSA-PKCS1-v1_5</span> | (@kkoyung, @jdm, #41172, #41225, #41240, #41267) |
+</figure>
+
+When using **servoshell** on Windows, you can now see `--help` and log output, as long as servoshell was started in a console.
+
+Servo diagnostics options are now accessible in servoshell via the `SERVO_DIAGNOSTICS` environment variable (@atbrakhi, #41013), in addition to the usual `-Z` / `--debug=` arguments.
+
+[**Servo’s devtools**](https://book.servo.org/contributing/devtools.html) now partially support the **Network** > **Security** tab (@jiang1997, #40567), allowing you to inspect some of the TLS details of your requests.
+We’ve also made it **compatible with Firefox 145** (@eerii, #41087), and use fewer IPC resources (@mrobinson, #41161).
+
+<figure>
+    <img src="{{ '/img/blog/2026-01-devtools-security.png' | url }}" alt="this website in Servo’s devtools, showing that the main request used TLS 1.3, TLS13_AES_256_GCM_SHA384 cipher suite, and X25519MLKEM768 key exchange, with HSTS enabled and HPKP disabled">
+</figure>
+
+We’ve fixed rendering bugs related to **‘float’**, **‘order’**, **‘max-width’**, **‘max-height’**, **‘:link’ selectors**, **&lt;audio> layout**, and **getClientRects()**, affecting intrinsic sizing (@Loirooriol, #41513), anonymous blocks (@Loirooriol, #41510), incremental layout (@Loirooriol, #40994), flex item sizing (@Loirooriol, #41291), selector matching (@andreubotella, #41478), replaced element layout (@Loirooriol, #41262), and empty fragments (@Loirooriol, #41477).
+
+Servo now fires **‘toggle’** events on **&lt;dialog>** (@lukewarlow, #40412).
+We’ve also improved the conformance of ‘wheel’ events (@mrobinson, #41182), ‘hashchange’ events (@Taym95, #41325), ‘dblclick’ events on &lt;input> (@Taym95, #41319), ‘resize’ events on &lt;video> (@tharkum, #40940), ‘seeked’ events on &lt;video> and &lt;audio> (@tharkum, #40981), and the ‘transform’ property in getComputedStyle() (@mrobinson, #41187).
+
+## Embedding API
+
+Servo now has basic support for **HTTP proxies** (@Narfinger, #40941).
+You can set the proxy URL in the `http_proxy` (@Narfinger, #41209) or `HTTP_PROXY` (@treeshateorcs, @yezhizhen, #41268) environment variables, or via `--pref network_http_proxy_uri`.
+
+We now use the **system root certificates** by default (@Narfinger, @mrobinson, #40935, #41179), on most platforms.
+If you don’t want to trust the system root certificates, you can instead continue to use Mozilla’s root certificates with `--pref network_use_webpki_roots`.
+As always, you can also add your own root certificates via [`Opts`](https://doc.servo.org/servo/opts/struct.Opts.html)::[`certificate_path`](https://doc.servo.org/servo/opts/struct.Opts.html#structfield.certificate_path) (`--certificate-path=`).
+
+We have a new [`SiteDataManager`](???) API for managing **localStorage**, **sessionStorage**, and **cookies** (@janvarga, #41236, #41255, #41378, #41523, #41528), and a new [`NetworkManager`](???) API for managing the **cache** (@janvarga, @mrobinson, #41255, #41474, #41386).
+To clear the cache, call [`NetworkManager`](???)::[`clear_cache`](???), and to list cache entries, call [`NetworkManager`](???)::[`cache_entries`](???).
+
+[**Simple dialogs**](https://html.spec.whatwg.org/multipage/#simple-dialogs) – that is alert(), confirm(), and prompt() – are now exposed to embedders via a new [`SimpleDialog`](https://doc.servo.org/servo/enum.SimpleDialog.html) type in [`EmbedderControl`](https://doc.servo.org/servo/webview_delegate/enum.EmbedderControl.html) (@mrobinson, @mukilan, #40982).
+This new interface is harder to misuse, and no longer requires boilerplate for embedders that wish to [ignore simple dialogs](https://html.spec.whatwg.org/multipage/#cannot-show-simple-dialogs).
+
+**Web console messages**, including messages from the [Console API](https://developer.mozilla.org/en-US/docs/Web/API/Console_API), are now accessible via [`ServoDelegate`](https://doc.servo.org/servo/trait.ServoDelegate.html)::[`show_console_message`](https://doc.servo.org/servo/trait.ServoDelegate.html#method.show_console_message) and [`WebViewDelegate`](https://doc.servo.org/servo/trait.WebViewDelegate.html)::[`show_console_message`](https://doc.servo.org/servo/trait.WebViewDelegate.html#method.show_console_message) (@atbrakhi, #41351).
+
+[`Servo`](https://doc.servo.org/servo/struct.Servo.html), the main handle for controlling Servo, is now cloneable for sharing within the same thread (@mukilan, @mrobinson, #41010).
+To shut down Servo, simply [drop](https://doc.rust-lang.org/std/mem/fn.drop.html) the last `Servo` handle or let it go out of scope.
+`Servo`::`start_shutting_down` and `Servo`::`deinit` have been removed (@mukilan, @mrobinson, #41012).
+
+Several interfaces have also been renamed:
+
+- [`Servo`](https://doc.servo.org/servo/struct.Servo.html)::`clear_cookies` is now [`SiteDataManager`](???)::[`clear_cookies`](???) (@janvarga, #41236, #41255)
+- `DebugOpts`::`disable_share_style_cache` is now [`Preferences`](https://doc.servo.org/servo/prefs/struct.Preferences.html)::[`layout_style_sharing_cache_enabled`](https://doc.servo.org/servo/prefs/struct.Preferences.html#structfield.layout_style_sharing_cache_enabled) (@atbrakhi, #40959)
+- The rest of `DebugOpts` has been moved to [`DiagnosticsLogging`](https://doc.servo.org/servo/opts/struct.DiagnosticsLogging.html), and the options have been renamed (@atbrakhi, #40960)
+
+## Perf and stability
+
+We can now **evict entries** from our **HTTP cache** (@Narfinger, @gterzian, @Taym95, #40613), rather than having it grow forever (or get cleared by an embedder).
+**about:memory** now tracks **SVG-related memory usage** (@d-kraus, #41481), and we’ve fixed memory leaks in &lt;video> and &lt;audio> (@tharkum, #41131).
+
+Servo now does less work when **matching selectors** (@webbeef, #41368), when **focus changes** (@mrobinson, @Loirooriol, #40984), and when **reflowing boxes** whose size did not change (@Loirooriol, @mrobinson, #41160).
+
+To allow for smaller binaries, **gamepad support** is now **optional at build time** (@WaterWhisperer, #41451).
+
+We’ve fixed some **undefined behaviour** around garbage collection (@sagudev, @jdm, @gmorenz, #41546, mozjs#688, mozjs#689, mozjs#692).
+To better avoid other garbage-collection-related bugs (@sagudev, <!-- ISSUE --> mozjs#647, mozjs#638), we’ve continued our work on defining (and migrating to) safer interfaces between Servo and the SpiderMonkey GC (@sagudev, #41519, #41536, #41537, #41520, #41564).
+
+We’ve fixed a crash that occurs when **&lt;link rel="shortcut icon">** has an **empty ‘href’ attribute**, which affected chiptune<!---->.com (@webbeef, #41056), and we’ve also fixed crashes in:
+
+- ‘background-repeat’ (@mrobinson, #41158)
+- &lt;audio> layout (@Loirooriol, #41262)
+- custom elements (@mrobinson, #40743)
+- AudioBuffer (@WaterWhisperer, #41253)
+- AudioNode (@Taym95, #40954)
+- ReportingObserver (@Taym95, #41261)
+- Uint8Array (@jdm, #41228)
+- the fonts system, on FreeType platforms (@simonwuelker, #40945)
+- IME usage, on OpenHarmony (@jschwe, #41570)
+
+## Donations
+
+Thanks again for your generous support!
+We are now receiving **7110 USD/month** (+10.5% over November) in recurring donations.
+This helps us cover the cost of our **[speedy](https://ci0.servo.org) [CI](https://ci1.servo.org) [and](https://ci2.servo.org) [benchmarking](https://ci3.servo.org) [servers](https://ci4.servo.org)**, one of our latest **[Outreachy interns](https://www.outreachy.org/alums/2025-06/#:~:text=Servo)**, and funding **[maintainer work]({{ '/blog/2025/09/17/your-donations-at-work-funding-jdm/' | url }})** that helps more people contribute to Servo.
+
+Servo is also on [thanks.dev](https://thanks.dev), and already **30 GitHub users** (+2 over November) that depend on Servo are sponsoring us there.
+If you use Servo libraries like [url](https://crates.io/crates/url/reverse_dependencies), [html5ever](https://crates.io/crates/html5ever/reverse_dependencies), [selectors](https://crates.io/crates/selectors/reverse_dependencies), or [cssparser](https://crates.io/crates/cssparser/reverse_dependencies), signing up for [thanks.dev](https://thanks.dev) could be a good way for you (or your employer) to give back to the community.
+
+We now have [**sponsorship tiers**]({{ '/blog/2025/11/21/sponsorship-tiers/' | url }}) that allow you or your organisation to donate to the Servo project with public acknowlegement of your support.
+A big thanks from Servo to our newest Bronze Sponsors: **Anthropy**, **Niclas Overby**, and **RxDB**!
+If you’re interested in this kind of sponsorship, please contact us at [[email protected]](mailto:[email protected]).
+
+<figure class="_fig" style="width: 100%; margin: 1em 0;"><div class="_flex" style="height: calc(1lh + 3em); flex-flow: column nowrap; text-align: left;">
+    <div style="position: relative; text-align: right;">
+        <div style="position: absolute; right: calc(100% - 100% * 7110 / 10000); padding-right: 0.5em;"><strong>7110</strong> USD/month</div>
+        <div style="position: absolute; margin-left: calc(100% * 7110 / 10000); height: calc(1lh + 1.5em); border-left: 1px solid;"></div>
+        <div style="position: absolute; margin-left: calc(100% - 0.5em); height: calc(1lh + 1.5em); border-left: 1px solid;"></div>
+        <div style="padding-right: 1em;"><strong>10000</strong><!-- USD/month --></div>
+    </div>
+    <progress value="7110" max="10000" style="transform: scale(3); transform-origin: top left; width: calc(100% / 3);"></progress>
+</div></figure>
+
+Use of donations is decided transparently via the Technical Steering Committee’s public **[funding request process](https://github.com/servo/project/blob/main/FUNDING_REQUEST.md)**, and active proposals are tracked in [servo/project#187](https://github.com/servo/project/issues/187).
+For more details, head to our [Sponsorship page]({{ '/sponsorship/' | url }}).
+
+## Conference talks and blogs
+
+[**Web engine CI on a shoestring budget**](https://www.youtube.com/watch?v=-W1mSXdlRqA) ([slides](https://www.azabani.com/talks/2025-12-18-shoestring-web-engine-ci/); [transcript](https://blogs.igalia.com/mrego/servo-a-new-web-engine-written-in-rust/)) — Delan Azabani (@delan) spoke about the CI system that keeps our builds and tryjobs moving fast.
+
+[**Servo 2025 Stats**](https://blogs.igalia.com/mrego/servo-2025-stats/) — Manuel Rego (@mrego) wrote about the growth of the Servo project, and how our many new contributors have enabled that.
+
+We have two **upcoming** talks at [**FOSDEM 2026**](https://fosdem.org/2026/) in **Brussels** later this month:
+
+[**The Servo project and its impact on the web platform ecosystem**](https://fosdem.org/2026/schedule/event/LXFKS9-servo-project-impact/) — Manuel Rego (@mrego) is speaking on **Saturday 31 January** at [**14:00 local time**](https://everytimezone.com/?t=697d4600,8ac) (13:00 UTC), about Servo’s impact on spec issues, interop bugs, test cases, and the broader web platform ecosystem.
+
+[**Implementing Streams Spec in Servo web engine**](https://fosdem.org/2026/schedule/event/3J8GUD-servo-streams-reimplementation/) — Taym Haddadi (@Taym95) is speaking on **Saturday 31 January** at [**17:45 local time**](https://everytimezone.com/?t=697d4600,98d) (16:45 UTC), about our experiences writing a new implementation of the [Streams API](https://developer.mozilla.org/en-US/docs/Web/API/Streams_API) that is independent of the one in SpiderMonkey.
+
+<style>
+    ._correction {
+        max-width: 33em;
+        margin: 1em auto;
+        border-bottom: 1px solid;
+        padding-bottom: 1em;
+    }
+    ._note {
+        margin: 1em 1em;
+        border-left: 1px solid;
+        padding-left: 1em;
+        opacity: 0.75;
+    }
+</style>
+
+<script>
+    (function makeVideoPlayersClickable() {
+        addEventListener("toggle", event => {
+            const details = event.target.closest("details");
+            if (!details?.open) {
+                return;
+            }
+            const video = details.querySelector("video");
+            if (!video) {
+                return;
+            }
+            if (video.fastSeek) {
+                video.fastSeek(0);
+            } else {
+                video.currentTime = 0;
+            }
+            video.play();
+        }, true);
+    })();
+</script>