{"id":8055,"date":"2017-02-16T09:00:31","date_gmt":"2017-02-16T17:00:31","guid":{"rendered":"http:\/\/blog.mozilla.org\/addons\/?p=8055"},"modified":"2017-05-18T10:46:26","modified_gmt":"2017-05-18T17:46:26","slug":"the-road-to-firefox-57-compatibility-milestones","status":"publish","type":"post","link":"https:\/\/blog.mozilla.org\/addons\/2017\/02\/16\/the-road-to-firefox-57-compatibility-milestones\/","title":{"rendered":"The Road to Firefox 57 &#8211; Compatibility Milestones"},"content":{"rendered":"<p><b>Update:<\/b> this post was updated to reflect a change in how we determine when Firefox will run in multiprocess mode. Firefox won\u2019t run in multiprocess mode unless add-ons are explicitly declared to be compatible with Multiprocess Firefox. Compatibility shims will be removed earlier than indicated in the previous version of this post.<\/p>\n<p><strong>Update 2:<\/strong> we can now confirm that this plan <a href=\"https:\/\/blog.mozilla.org\/addons\/2017\/05\/18\/compatibility-update-android\/\">also applies to Firefox for Android<\/a>.<\/p>\n<p>Back in November, we laid out our <a href=\"https:\/\/blog.mozilla.org\/addons\/2016\/11\/23\/add-ons-in-2017\/\" target=\"_blank\" rel=\"noopener noreferrer\">plans for add-ons in 2017<\/a>. Notably, we defined Firefox 57 as the first release where only <a href=\"https:\/\/developer.mozilla.org\/en-US\/Add-ons\/WebExtensions\" target=\"_blank\" rel=\"noopener noreferrer\">WebExtensions<\/a> will be supported. In parallel, the deployment of <a href=\"https:\/\/developer.mozilla.org\/en-US\/Firefox\/Multiprocess_Firefox\" target=\"_blank\" rel=\"noopener noreferrer\">Multiprocess Firefox<\/a> (also known as e10s) continues, with many users already benefiting from the performance and stability gains. There is a lot going on and we want you to know what to expect, so here is an update on the upcoming compatibility milestones.<\/p>\n<p>We\u2019ve been working on setting out a simple path forward, minimizing the compatibility hurdles along the way, so you can focus on migrating your add-ons to <a href=\"https:\/\/developer.mozilla.org\/en-US\/Add-ons\/WebExtensions\" target=\"_blank\" rel=\"noopener noreferrer\">WebExtensions<\/a>.<\/p>\n<h3>Legacy add-ons<\/h3>\n<p>By <i>legacy add-ons<\/i>, we\u2019re referring to:<\/p>\n<ul>\n<li>All extensions that aren&#8217;t WebExtensions. Specifically: <a href=\"https:\/\/developer.mozilla.org\/en-US\/Add-ons\/Overlay_Extensions\" target=\"_blank\" rel=\"noopener noreferrer\">XUL overlay extensions<\/a>, <a href=\"https:\/\/developer.mozilla.org\/en-US\/Add-ons\/Bootstrapped_extensions\" target=\"_blank\" rel=\"noopener noreferrer\">bootstrapped extensions<\/a>, <a href=\"https:\/\/developer.mozilla.org\/en-US\/Add-ons\/SDK\" target=\"_blank\" rel=\"noopener noreferrer\">SDK extensions<\/a>, and <a href=\"https:\/\/developer.mozilla.org\/en-US\/Add-ons\/WebExtensions\/Embedded_WebExtensions\" target=\"_blank\" rel=\"noopener noreferrer\">Embedded WebExtensions<\/a>.<\/li>\n<li>Complete themes. These add-ons shouldn\u2019t have problems with multiprocess compatibility but will follow the same compatibility milestones as other legacy add-ons. We will provide more details on what\u2019s coming for themes very soon in this blog.<\/li>\n<\/ul>\n<p>Language packs, dictionaries, OpenSearch providers, lightweight themes, and add-ons that only support Thunderbird or SeaMonkey aren\u2019t considered legacy.<\/p>\n<h3>Firefox 53, April 18th release<\/h3>\n<ul>\n<li><del>Firefox will run in multiprocess mode by default for all users, with some exceptions. If your add-on has the <a href=\"https:\/\/developer.mozilla.org\/en-US\/Add-ons\/Install_Manifests#multiprocessCompatible\" target=\"_blank\" rel=\"noopener noreferrer\">multiprocessCompatible flag<\/a> set to false, Firefox will run in single process mode if the add-on is enabled.<\/del><\/li>\n<li><del>Add-ons that are reported and confirmed as incompatible with Multiprocess Firefox (and don\u2019t have the flag set to false) will be marked as incompatible and disabled in Firefox.<\/del><\/li>\n<li>Unless your add-on has the<a href=\"https:\/\/developer.mozilla.org\/en-US\/Add-ons\/Install_Manifests#multiprocessCompatible\"> multiprocessCompatible flag<\/a> set to true or is a WebExtension, Firefox will run in single process mode. Firefox will run in multiprocess mode if all enabled add-ons meet this criteria.<\/li>\n<li>Add-ons will only be able to <a href=\"https:\/\/blog.mozilla.org\/addons\/2017\/01\/24\/preventing-add-ons-third-party-software-from-loading-dlls-into-firefox\/\" target=\"_blank\" rel=\"noopener noreferrer\">load binaries<\/a> using the Native Messaging API.<\/li>\n<li>No new legacy add-ons will be accepted on <a href=\"https:\/\/addons.mozilla.org\" target=\"_blank\" rel=\"noopener noreferrer\">addons.mozilla.org<\/a> (AMO). Updates to existing legacy add-ons will still be accepted.<\/li>\n<\/ul>\n<h3>Firefox 54-56<\/h3>\n<ul>\n<li>Legacy add-ons that work with Multiprocess Firefox in 53 may still run into compatibility issues due to followup work:\n<ul>\n<li><a href=\"https:\/\/wiki.mozilla.org\/Firefox\/AddOns\/Status\/current#Multiplecontent_Processes\" target=\"_blank\" rel=\"noopener noreferrer\">Multiple content processes<\/a> is being launched in <a href=\"https:\/\/wiki.mozilla.org\/RapidRelease\/Calendar#Future_branch_dates\" target=\"_blank\" rel=\"noopener noreferrer\">Firefox 55<\/a>. This enables multiple content processes, instead of the single content process currently used.<\/li>\n<li><a href=\"https:\/\/wiki.mozilla.org\/Firefox\/AddOns\/Status\/current#Sandboxing\" target=\"_blank\" rel=\"noopener noreferrer\">Sandboxing<\/a> will be launched in Firefox 54. Additional security restrictions will prevent certain forms of file access from content processes.<\/li>\n<\/ul>\n<\/li>\n<li>Multiprocess compatibility shims are removed from Firefox, starting with the Nightly and Developer Edition channels.<\/li>\n<\/ul>\n<h3>Firefox 57, November 14th release<\/h3>\n<ul>\n<li>Firefox will only run WebExtensions.<\/li>\n<li>AMO will continue to support listing and updating legacy add-ons after the release of 57 in order to have an easier transition. The exact cut-off time for this support hasn\u2019t been determined yet.<\/li>\n<li><del>Multiprocess compatibility shims are removed from Firefox. This doesn\u2019t affect WebExtensions, but it\u2019s one of the reasons went with this timeline.<\/del><\/li>\n<\/ul>\n<p>For all milestones, keep in mind that Firefox is released using a \u201ctrain\u201d model, where <a href=\"https:\/\/www.mozilla.org\/en-US\/firefox\/channel\/desktop\/\" target=\"_blank\" rel=\"noopener noreferrer\">Beta, Developer Edition, and Nightly<\/a> correspond to the future 3 releases. You should expect users of pre-release versions to be impacted by these changes earlier than their final release dates. The <a href=\"https:\/\/wiki.mozilla.org\/RapidRelease\/Calendar\" target=\"_blank\" rel=\"noopener noreferrer\">Release Calendar<\/a> lists future release dates per channel.<\/p>\n<p>We are committed to this timeline, and will work hard to make it happen. We urge all developers to look into <a href=\"https:\/\/developer.mozilla.org\/en-US\/Add-ons\/WebExtensions\" target=\"_blank\" rel=\"noopener noreferrer\">WebExtensions<\/a> and <a href=\"https:\/\/developer.mozilla.org\/en-US\/Add-ons\/WebExtensions\/Porting_a_legacy_Firefox_add-on\" target=\"_blank\" rel=\"noopener noreferrer\">port<\/a> their add-ons as soon as possible. If you think your add-on can\u2019t be ported due to missing APIs, <a href=\"https:\/\/blog.mozilla.org\/addons\/2016\/11\/03\/more-ways-to-contribute-to-webextensions\/\" target=\"_blank\" rel=\"noopener noreferrer\">here\u2019s how you can let us know<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Update: this post was updated to reflect a change in how we determine when Firefox will run in multiprocess mode. Firefox won\u2019t run in multiprocess mode unless add-ons are explicitly &hellip; <a class=\"go\" href=\"https:\/\/blog.mozilla.org\/addons\/2017\/02\/16\/the-road-to-firefox-57-compatibility-milestones\/\">Read more<\/a><\/p>\n","protected":false},"author":173,"featured_media":7560,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[44,295,278886],"tags":[278877,278873,278876,45292,288922,288923,278871],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v22.5 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>The Road to Firefox 57 - Compatibility Milestones - Mozilla Add-ons Community Blog<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/blog.mozilla.org\/addons\/2017\/02\/16\/the-road-to-firefox-57-compatibility-milestones\/\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Jorge Villalobos\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"3 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/blog.mozilla.org\/addons\/2017\/02\/16\/the-road-to-firefox-57-compatibility-milestones\/\",\"url\":\"https:\/\/blog.mozilla.org\/addons\/2017\/02\/16\/the-road-to-firefox-57-compatibility-milestones\/\",\"name\":\"The Road to Firefox 57 - Compatibility Milestones - Mozilla Add-ons Community Blog\",\"isPartOf\":{\"@id\":\"https:\/\/blog.mozilla.org\/addons\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/blog.mozilla.org\/addons\/2017\/02\/16\/the-road-to-firefox-57-compatibility-milestones\/#primaryimage\"},\"image\":{\"@id\":\"https:\/\/blog.mozilla.org\/addons\/2017\/02\/16\/the-road-to-firefox-57-compatibility-milestones\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/blog.mozilla.org\/addons\/files\/2015\/09\/foxface_puzzle.jpg\",\"datePublished\":\"2017-02-16T17:00:31+00:00\",\"dateModified\":\"2017-05-18T17:46:26+00:00\",\"author\":{\"@id\":\"https:\/\/blog.mozilla.org\/addons\/#\/schema\/person\/a098261b4b5510d408ff31f492606925\"},\"breadcrumb\":{\"@id\":\"https:\/\/blog.mozilla.org\/addons\/2017\/02\/16\/the-road-to-firefox-57-compatibility-milestones\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/blog.mozilla.org\/addons\/2017\/02\/16\/the-road-to-firefox-57-compatibility-milestones\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/blog.mozilla.org\/addons\/2017\/02\/16\/the-road-to-firefox-57-compatibility-milestones\/#primaryimage\",\"url\":\"https:\/\/blog.mozilla.org\/addons\/files\/2015\/09\/foxface_puzzle.jpg\",\"contentUrl\":\"https:\/\/blog.mozilla.org\/addons\/files\/2015\/09\/foxface_puzzle.jpg\",\"width\":945,\"height\":922},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/blog.mozilla.org\/addons\/2017\/02\/16\/the-road-to-firefox-57-compatibility-milestones\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/blog.mozilla.org\/addons\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"The Road to Firefox 57 &#8211; 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