See what landed recently in Firefox Nightly!

Starting with Firefox 154, we're testing a simpler tab context menu in Firefox Labs. It can be turned on in Settings > Firefox Labs > Streamline tab menu, and feedback is welcome on Mozilla Connect.

Fixed Firefox preventing Linux systems from sleeping or suspending after a long browsing session.

The emulation options have moved into a new emulation panel, available behind the @ button in the Rules View, which also offers new toggles to emulate the prefers-reduced-motion media feature.

Starting with Firefox 154, Firefox Nightly now supports the alpha() CSS function. This is a relative color function that can be used to modify just the alpha component of a given color.

Starting with Firefox 153, Firefox Nightly ships an experimental implementation of the link-parameters property by Tyler Thrailkill.

Starting with Firefox 153, Firefox Nightly now supports two new keywords, closest-corner and farthest-corner, for the radial size in the circle() and ellipse() functions.

Starting with Firefox 154, Firefox Nightly now supports QUIC version 2 (RFC 9369) for HTTP/3 connections. Firefox offers both QUIC v1 and v2 using compatible version negotiation (RFC 9368). The server selects which version is used, so connections upgrade to QUIC v2 when the server chooses it and remain on QUIC v1 otherwise.

Firefox now supports the progress() CSS function. This is a math function that can be used in calculations to compute the position of a value relative to a start and an end.

SVG <a> elements now expose the same URL properties as HTML links, including protocol, host, pathname, and search.

Starting with Firefox 155, the RegExp Buffer Boundary proposal is now available for testing in Nightly builds by setting the javascript.options.experimental.regexp_buffer_boundaries preference.