Firefox Developer Version

Any version of Firefox Developer Edition distributed on Uptodown is completely virus-free and free to download at no cost. 88.0b9 Apr 13th, 2021 88.0b4 (64-bit). Any version of Firefox Developer Edition distributed on Uptodown is completely virus-free and free to download at no cost. 88.0b9 Apr 13th, 2021 88.0b4 (64-bit) Mar 30th, 2021 87.0b8 (64-bit) Mar 10th, 2021. Firefox Developer Edition 89.0b1 is available to all software users as a free download for Windows. As an open source project, you are free to view the source code and distribute this software application freely. The program was created by the developer as a freeware product, but donations for the continued development are highly appreciated.

Firefox Developer Version History
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Firefox For Developer Download

This article is for IT Admins who want to configure Firefox on their organization's computers.

Firefox Enterprise includes several software solutions made by Mozilla for specific Enterprise needs. Together, these software solutions make up Firefox Enterprise.

The Firefox browser

You can select the Firefox Rapid Release channel (the version most consumers use) or the Firefox Extended Support Release channel (longer support cycles) depending on your needs. This article will help you understand how to select the channel that best matches your needs.

The MSI installer

We created a MSI wrapper of the full installer exe in order to simplify deployments for active directory users in need of a Mozilla signed MSI. Find-out more about the MSI installer here.

ADM and AMDX templates

We created a ADM/ADMX templates (Windows group policy template) with standard best practices in order to illustrate how group policies can be used on Windows. Find-out more about the use of ADM/ADMX templates here.

The “Open in IE” extension

Some corporations still use ActiveX technologies or websites that are only tested against IE. This extension helps you determine which URLs should be opened in IE automatically by your users. Find-out more details about the “Open in IE” extension here.

MacOS plist file

We created a plist template (MacOS policy management template) with standard best practices in order to illustrate how policies can be managed on MacOS. Find-out more about the use of plist templates here.

Configuration JSON file “policies.json”

Even though we support GPO on Windows and plist on MacOS, you can still use a configuration file if it suits your needs (Linux machines?). Find-out more here about how you can deploy customizations using policies.json.

This article provides information about the changes in Firefox 78 that will affect developers. Firefox 78 was released on June 30, 2020.

See also New in Firefox 78: DevTools improvements, new regex engine, and abundant web platform updates on Mozilla hacks.

Changes for web developers

Developer Tools

Debugger

You can now change the URL accessed by the remote device from the about:debugging panel. (bug 1617237)
The Disable JavaScript menu item in the Debugger now only affects the current tab, and is reset when the Developer Tools are closed. (bug 1640318)
Logpoints can map variable names in source-mapped code back to their original names, if you enable Maps in the Scopes pane. (bug 1536857)

Network Monitor

In the Network Monitor, you can now resize the columns of the request list by dragging the column borders anywhere in the table. (bug 1618409)
The request details panel in the Network Monitor has some UX improvements. (bug 1631302, bug 1631295)
If a request was blocked, the request list now shows the reason, such as an add-on, CSP, CORS, or Enhanced Tracking Protection. (bug 1555057, bug 1445637, bug 1556451)

Other tools

The Accessibility inspector is out of beta. You can use it to check for various accessibility issues on your site. (bug 1602075)
Uncaught promise errors now provide all details in the Console, including their name and stack. (bug 1636590)

CSS

The :is() and :where() pseudo-classes are now enabled by default (bug 1632646).
The :read-only and :read-write pseudo-classes are now supported without prefixes (bug 312971).
- In addition, :read-write styles are no longer applied to disabled <input> and <textarea> elements, which was a violation of the HTML spec (bug 888884).

JavaScript

The Intl.ListFormat API is now supported (bug 1589095).
The Intl.NumberFormat() constructor has been extended to support new options specified in the Intl.NumberFormat Unified API Proposal (bug 1633836). This includes among other things:
- Unit, currency and sign display formatting
The RegExp engine has been updated and now supports all new features introduced in ECMAScript 2018:
- Lookbehind assertions (bug 1225665)
- RegExp.prototype.dotAll (bug 1361856)
- Unicode property escapes (bug 1361876)
- Named capture groups (bug 1362154)
Due to a WebIDL spec change in mid-2020, we've added a Symbol.toStringTag property to all DOM prototype objects (bug 1277799).
The garbage collection of WeakMap objects has been improved. WeakMaps are now marked incrementally (bug 1167452).

APIs

DOM

The ParentNode.replaceChildren() method has been implemented (bug 1626015).

Service workers

Extended Support Releases (ESR): Firefox 78 is the first ESR release that supports Service workers (and the Push API). Earlier ESR releases had no support (bug 1547023).

WebAssembly