Mozilla plans to make Firefox 60 the next ESR (Extended Support Release) version of the Firefox web browser, and not Firefox 59.
New major Firefox versions are released every six to eight weeks. Mozilla introduced a fixed six week rapid release cycle back in 2011, but switched to a flexible 6-8 week release cycle in 2016.
The organization introduced Firefox ESR specifically for organizations to increase the time between major releases. Firefox ESR is available for organizations and home users. While ESR versions of Firefox do get security and bug fix updates whenever a new major version of Firefox is released, feature updates are only introduced after several release cycles.
The next major Firefox ESR update was scheduled to be Firefox 59, but it appears that Mozilla will postpone the move to Firefox 60.
Note: Plans may change. We will update the article if changes to the schedule are announced.
Firefox 60 ESR
The main source that indicates that Mozilla plans to make Firefox 60 the next ESR candidate is the EnterprisePolicies page on the Mozilla Wiki website.
We want to make customization of Firefox deployments simpler for system administrators and we want our next ESR version, Firefox 60, to include a policy engine that increases customization possibilities and integration into existing management systems.
Mozilla reveals the reason why Firefox 60 is the next ESR target on the same page.
Our key objective is to meet the demand for enterprise customization post-57 in time for the next ESR.
System administrators could use CCK2 Wizard in Firefox 52 ESR and earlier versions to configure Firefox before distribution. The switch to WebExtensions exclusivity in Firefox 57 makes the add-on incompatible with the next Firefox ESR version, regardless of whether it is Firefox 59 or Firefox 60.
Mozilla has to create new options for the large scale deployment of Firefox, and the organization’s answer is Enterprise Policies. The new policy engine won’t be limited to Firefox ESR.
The Policy Engine will be a component in Firefox that reads some admin-specified configuration during Firefox’s startup and properly configures features to respect those configurations.
The new engine uses .json files initially, but Mozilla plans to support operating system level administration features such as Windows’ Group Policy later on. The plan is to implement support in the json configuration file first before implementing the “most important ones” through GPO.
Mozilla is still working on the list of policies. Discussed right now are policies to disable Telemetry, disable features such as Pocket, Printing, or Firefox Screenshots, whitelist and block domains, pre-populate permissions, add bookmarks, or disable internal configuration features such as about:config or about:addons. (via Sören Hentzschel)