{"id":366,"date":"2026-10-20T09:00:30","date_gmt":"2026-10-20T16:00:30","guid":{"rendered":"https:\/\/devblogs.microsoft.com\/insidemsix\/?p=366"},"modified":"2026-10-19T14:30:56","modified_gmt":"2026-10-19T21:30:56","slug":"activatable-extension-points","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/insidemsix\/activatable-extension-points\/","title":{"rendered":"Activatable Extension Points"},"content":{"rendered":"

We often talk about “running an application”<\/strong>, “launching an app”<\/strong>, or “starting an app”<\/strong>. This conjures up visions of CreateProcess()<\/code> spinning up a new process, giving the application life.<\/p>\n

For packaged applications, Windows has a specific term for bringing an application to life: activation.<\/p>\n

Bringing a packaged process<\/a> to life involves more than ordinary unpackaged process<\/a> creation. Windows calls this machine “activation”.<\/p>\n

Activation does more than simply create a process. Among other things, it creates the new process with the appropriate package identity<\/a>. Activation also verifies the package is in an appropriate state<\/a> before starting the process and can initiate repair (also known as remediation) when it isn’t.<\/p>\n

Activatable Extension Points<\/h1>\n

There’s more that can be activated than applications. An activatable extension point defines something Windows can activate. <Application><\/a> declarations and certain <Extension><\/a> declarations represent activatable extension points. These declarations can cause Windows to activate a packaged process.1<\/sup><\/p>\n

Activation is the mechanism Windows uses to start a packaged process through an activatable extension point. This includes obvious scenarios such as launching a packaged application from the Start menu or double-clicking a file in File Explorer whose file type is associated with a packaged application2<\/sup>. It also includes less obvious scenarios, such as instantiating a COM or WinRT out-of-process (OOP) object hosted by a packaged process3<\/sup>.<\/p>\n

\n

1<\/sup> Manifested Extension<\/code> elements can appear in many namespaces. For example, <uap17:extension Category=”windows.packageExtension”><\/a>, <com4:extension Category=”windows.comServer”><\/a> and <desktop9:extension Category=”windows.fileExplorerClassicContextMenuHandler”><\/a> are all examples of <Extension><\/code> declarations.<\/p>\n

2<\/sup> Examples include <uap:extension Category=”windows.fileTypeAssociation”><\/a>.<\/p>\n

3<\/sup> Examples include <com4:extension Category=”windows.comServer”><\/a> or <uap5:extension Category=”windows.hostRuntime”><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

We often talk about “running an application”, “launching an app”, or “starting an app”. This conjures up visions of CreateProcess() spinning up a new process, giving the application life. For packaged applications, Windows has a specific term for bringing an application to life: activation. Bringing a packaged process to life involves more than ordinary unpackaged […]<\/p>\n","protected":false},"author":911,"featured_media":81,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[28,8,9,2,34,10],"class_list":["post-366","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-msix","tag-activation","tag-architecture","tag-code","tag-msix","tag-runtime","tag-terminology"],"acf":[],"blog_post_summary":"

We often talk about “running an application”, “launching an app”, or “starting an app”. This conjures up visions of CreateProcess() spinning up a new process, giving the application life. For packaged applications, Windows has a specific term for bringing an application to life: activation. Bringing a packaged process to life involves more than ordinary unpackaged […]<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/insidemsix\/wp-json\/wp\/v2\/posts\/366","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/insidemsix\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/insidemsix\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/insidemsix\/wp-json\/wp\/v2\/users\/911"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/insidemsix\/wp-json\/wp\/v2\/comments?post=366"}],"version-history":[{"count":2,"href":"https:\/\/devblogs.microsoft.com\/insidemsix\/wp-json\/wp\/v2\/posts\/366\/revisions"}],"predecessor-version":[{"id":379,"href":"https:\/\/devblogs.microsoft.com\/insidemsix\/wp-json\/wp\/v2\/posts\/366\/revisions\/379"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/insidemsix\/wp-json\/wp\/v2\/media\/81"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/insidemsix\/wp-json\/wp\/v2\/media?parent=366"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/insidemsix\/wp-json\/wp\/v2\/categories?post=366"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/insidemsix\/wp-json\/wp\/v2\/tags?post=366"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}