Mozilla Releases New Trainspotting Blog Series to Track Firefox Releases

The Firefox team is hosting a new blog series called Trainspotting on Mozilla Hacks which is designed to help Web developers keep up with what’s new, what’s changed and what is coming soon in all of the Firefox's, the Web platform, and the Mozilla tools for building the Web.

The Trainspotting name comes from the way Mozilla develops Gecko and Firefox on a “train model” as they branch the code and ship a release on a time-based schedule which is every six weeks. If a feature is not finished, it’s reverted or disabled and has to, as the team says, “ride the next train.” This means they ship new features, performance improvements, and bug fixes to users every six weeks. Trainspotting will publish every six weeks, concurrent with the releases.

The first issue of Trainspotting focuses on the release of Firefox 37. A list of notable features is included here.

- A subset of the Media Source Extensions (MSE) API has been implemented and is enabled to allow native playback of HTML5 video on websites such as YouTube. 

- Bing search now uses HTTPS.

- Heartbeat is a new feedback feature in Firefox desktop: Each day a random subset of Firefox users will be shown a notification bar with an opportunity to provide feedback on their experience.

For this release Firefox for Android is getting a security and stability release. The biggest user-facing changes include improved performance of file downloads, and the addition of new locales including Albanian, Burmese, Lower Sorbian, Songhai, Upper Sorbian, and Uzbek. 

There are a number of new Web platform features that can be used in production content in Firefox 37 including: IndexedDB is now available in Web Workers and display:contents is now supported in CSS. 

The new Security Panel in the Network Monitor shows security details for a network request, such as which cipher was negotiated for each resource, and more. The new UI also shows if connections were protected by HTTP strict-transport-security or key pinning.  The new Animations panel in the Page Inspector displays information about animations and provides a play/pause button for them. WebIDE can now run a custom build step before pushing apps to a device, in case a developer wants to minify code or integrate with a Web app build tool of choice. 

Firefox 37 has a number of security changes. Most of these do not require any action, however site operators should look to see if they are impacted by any of the changes. 

In six weeks Firefox Beta will be available for general release, becoming Firefox 38. Here’s some of what’s coming through the pipeline:

- All Firefox preferences are offered in a new tab-based UI.

- Improved page-load times with speculative connection warmup.

- MSE support on Mac OS X.

- EME support for encrypted media playback.

- Web platform features: WebSockets in Web Workers, KeyboardEvent.code, and the BroadcastChannel API.

This release of Firefox Developer edition, which will be Firefox 39, will offer the following:

- Developer Tools: Wi-Fi debugging of Firefox OS devices from WebIDE, drag and drop of nodes in the Inspector’s markup view, Web Console input history persistence, localhost works with WebSocket connections when offline, and the cubic bezier tooltip will show a gallery of pre-sets to choose from to make CSS animations super slick.

- Web platform features include the “switch” role in Aria 1.1, CSS scroll snap points, Cache API, Fetch API, and more.

The nightly branch of Firefox is where a lot of features are in active development. It’s a place where developers can test experimental Web APIs and see user-facing browser features that are not yet ready for prime time. There are a number of features that have landed and are shipping nightly builds either enabled by default or by pref:

- E10s: Web content runs in a separate process from the browser UI.

- Partial implementation of Service Workers.

- Shumway: Flash implemented in JavaScript is enabled for some sites.