Mozilla drops support for binary components in extensions

In what appears to be a rather rushed decision, Mozilla disabled supported for binary XPCOM components in extensions in the Gecko engine when Firefox 40 is released.

While it is being introduced with the release of Firefox 40 Stable, it will affect all Gecko-based programs including Mozilla Thunderbird.

Mozilla justified the change in a blog post yesterday stating that binary XPCOM components are unstable and are a cause for instability especially in Firefox.

The organization notes that most add-on developers have moved away already from using these binary components and that it has added support for native binaries to the addon SDK directly instead.

The number of extensions affected by the change is unclear at this point in time. The calendar add-on Lightning is probably the most popular extension that still relies on binary XPCOM components.

The change comes at a rather inappropriate time for Lightning as the Thunderbird team plans to ship it with version 38 of the email client.

The owner of Lightning chimed in and revealed that a switch from binary components to JavaScript would impact performance big time stating that code execution for some routines would jump from a few hundred milliseconds to six seconds.

The only other quick fix available would be to integrate the binary component directly into Thunderbird, as clients retain access to it while extensions don't. But this would result in issues for other compatible applications such as SeaMonkey as this would have to be done in those programs as well.

One favorable solution right now would be to add a configure-level flag instead of shutting down access altogether right away. This would give extension developers more time to address the issue and rewrite code to ensure compatibility with version 40 and beyond of Firefox and Thunderbird.

It is unclear how Firefox forks or spin-offs like Pale Moon will handle the change.

So what is the worst case scenario?

Extensions that rely on binary components will stop working when Firefox 40 and Thunderbird 40 are released. The only exception right now are B2G released.

If Mozilla implements a flag for Thunderbird to bypass the restriction for the time being, then it should give extension developers more time to find a suitable solution without breaking extensions when Thunderbird 40 hits.

Firefox 40 will be released in August 2015.

Now You: Are you impacted by the change?