files/en-us/mozilla/firefox/releases/45/index.md
To test the latest developer features of Firefox, install Firefox Developer Edition Firefox 45 was released on March 8, 2016. This article lists key changes that are useful not only for web developers, but also Firefox and Gecko developers as well as add-on developers.
Highlights:
All devtools bugs fixed between Firefox 43 and Firefox 44.
referrer has been renamed referrerpolicy on {{HTMLElement("img")}}, {{HTMLElement("area")}}, {{HTMLElement("a")}}, and {{HTMLElement("iframe")}} (Firefox bug 1187357).{{cssxref("word-spacing")}} now allows percentage values (Firefox bug 1038663).
Our implementation of CSS Grids has been improved and is no more considered experimental; it is now activated by default in nightly and developer edition, but not for beta and release (Firefox bug 1000592):
grid-column-gap, grid-row-gap, and grid-gap properties are now supported (Firefox bug 1176792).auto behavior has been implemented (Firefox bug 1176775).Implement full support for CSS Box Alignment for CSS Grid, support the missing values: start, end, self-start, self-end, left, right, last-baseline, space-evenly (Firefox bug 1176782). CSS Box Alignment currently applies only to CSS Flexbox and CSS Grid.
[css-grid][css-flexbox] Implement grid/flex layout for <fieldset> (Firefox bug 1230207).
The inline-start and inline-end values have been added to {{cssxref("float")}} and {{cssxref("clear")}} (Firefox bug 1122918). They are enabled by default on Nightly and Aurora (Dev edition), as well as on Firefox OS; to activate it on a release or beta version, you need to flip the layout.css.float-logical-values.enabled to true.
The {{cssxref("text-emphasis")}}, {{cssxref("text-emphasis-style")}}, {{cssxref("text-emphasis-color")}}, and {{cssxref("text-emphasis-position")}} have been implemented; they are disabled by default (set layout.css.text-emphasis.enabled to true to activate them (Firefox bug 1040668).
Several -webkit prefixed properties and values have been added for web compatibility, behind the preference layout.css.prefixes.webkit, defaulting to false:
-webkit-backface-visibility, -webkit-perspective and -webkit-perspective-origin for web compatibility, behind the preference layout.css.prefixes.webkit, defaulting to false (Firefox bug 1179444).Node.innerText has been implemented (Firefox bug 264412).Our implementation of WebGL 2 has been extended:
No change.
includeUncontrolled property. This is a boolean value — if set to true, the matching operation will return all service worker clients who share the same origin as the current service worker. Otherwise, it returns only the service worker clients controlled by the current service worker. The default is false.No change.
No change.
ComputedTiming have been added to our experimental implementation of Web Animations API (Firefox bug 1108055).No change.
jar: protocol has been disabled by default when accessed from Web content; you may enable this if necessary by setting the network.jar.block-remote-files preference to false (Firefox bug 1215235).No change.
No change.
No change.
Starting in Firefox 45, search plugins located in the user's profile's searchplugins directory are no longer automatically loaded on startup. Instead, a list of user-installed plugins is maintained and only those plugins are loaded. In effect, this means that the only ways to install new search plugins are for the user to do so in the Firefox UX (via OpenSearch discovery, for instance) or for an add-on to install it. Also, when a new search plugin is installed, more information is recorded about where it came from, for future use by profile debugging and cleaning tools.