# December in Servo: multiple windows, proxy support, better caching, and more!

DevFeed: [December in Servo: multiple windows, proxy support, better caching, and more!](<https://devfeed.tech/articles/december-in-servo-multiple-windows-proxy-support-better-caching-and-more-3539.md>)

Original publisher: [Read original article](<https://servo.org/blog/2026/01/23/december-in-servo/>)

Author: The Servo Project Developers

Published: 2026-01-23T00:00:00Z

Content type: release

Language: en

Sources: [Servo Blog](<https://devfeed.tech/sources/servo-blog.md>)

Topics: [servo engine](<https://devfeed.tech/topics/servo-engine.md>), [modern web development](<https://devfeed.tech/topics/modern-web-development.md>), [Web Development](<https://devfeed.tech/topics/web-development.md>), [Developer Tools](<https://devfeed.tech/topics/developer-tools.md>)

Tags: [api](<https://devfeed.tech/tags/api.md>), [bugs](<https://devfeed.tech/tags/bugs.md>), [css](<https://devfeed.tech/tags/css.md>), [debug](<https://devfeed.tech/tags/debug.md>), [diagnostics](<https://devfeed.tech/tags/diagnostics.md>), [embedding](<https://devfeed.tech/tags/embedding.md>), [events](<https://devfeed.tech/tags/events.md>), [firefox](<https://devfeed.tech/tags/firefox.md>), [http](<https://devfeed.tech/tags/http.md>), [macos](<https://devfeed.tech/tags/macos.md>), [meta](<https://devfeed.tech/tags/meta.md>), [mozilla](<https://devfeed.tech/tags/mozilla.md>), [network-security](<https://devfeed.tech/tags/network-security.md>), [rust](<https://devfeed.tech/tags/rust.md>), [security](<https://devfeed.tech/tags/security.md>), [servo](<https://devfeed.tech/tags/servo.md>), [servo-engine](<https://devfeed.tech/tags/servo-engine.md>), [servo-rendering-engine](<https://devfeed.tech/tags/servo-rendering-engine.md>), [streams](<https://devfeed.tech/tags/streams.md>), [tls](<https://devfeed.tech/tags/tls.md>), [web](<https://devfeed.tech/tags/web.md>), [web-browser](<https://devfeed.tech/tags/web-browser.md>), [web-browser-engine](<https://devfeed.tech/tags/web-browser-engine.md>), [web-engine](<https://devfeed.tech/tags/web-engine.md>), [web-platform](<https://devfeed.tech/tags/web-platform.md>), [web-rendering-engine](<https://devfeed.tech/tags/web-rendering-engine.md>), [windows](<https://devfeed.tech/tags/windows.md>)

## AI overview

Servo 0.0.4 and December nightly builds add multiple-window support, HTTP proxy configuration, web-platform compatibility updates, expanded SubtleCrypto support, and developer-tool improvements.

## Source excerpt

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. 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 <meta charset> (@simonwuelker, #41376) partial support for encoding sniffing (@simonwuelker, #41435) 'background' and 'bgcolor' attributes on <table>, <thead>, <tbody>, <tfoot>, <tr>, <td>, <th> (@simonwuelker, #41272) tee() on readable byte streams (@Taym95, #35991) Note: due to a known issue, servoshell on macOS may not be able to directly open new windows, depending on your system settings. 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 API, 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): Algorithm ChaCha20-Poly1305 (@kkoyung, #40978, #41003, #41030) RSA-OAEP (@kkoyung, @TimvdLippe, @jdm, #41225, #41217, #41240, #41316) RSA-PSS (@kkoyung, @jdm, #41157, #41225, #41240, #41287) RSASSA-PKCS1-v1_5 (@kkoyung, @jdm, #41172, #41225, #41240, #41267) When using servoshell on Windows, you can now see --help and log output, as long as servoshell was started in a console (@jschwe, #40961). 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 now partially support the Network > Security tab (@jiang1997, #40567), allowing you to inspect some of the TLS details of you