diff --git a/manifests/Mozilla/FirefoxDeveloperEdition/77.0b9.yaml b/manifests/Mozilla/FirefoxDeveloperEdition/77.0b9.yaml
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+# ================== General ==================
+
+Id: Mozilla.FirefoxDeveloperEdition
+Publisher: Mozilla
+Name: Firefox Developer Edition
+AppMoniker: firefox
+Description: Firefox Developer Edition is the blazing fast browser that offers cutting edge developer tools and latest features like CSS Grid support and framework debugging
+Homepage: https://www.mozilla.org/en-US/firefox/developer/
+Tags: Browser, Mozilla, Firefox, Developer
+
+Version: 77.0b9
+
+License: Mozilla Public License Version 2.0
+LicenseUrl: https://www.mozilla.org/en-US/MPL/2.0/
+
+# ================= Installer =================
+
+InstallerType: exe
+Installers:
+  - Arch: x64
+    Url: https://download-installer.cdn.mozilla.net/pub/devedition/releases/77.0b9/win64/en-US/Firefox%20Setup%2077.0b9.exe
+    Sha256: F62287080E5DD5D6E93BAB3021866FDBA901B8A4112F45BAAE7F689EB271637B
+    Switches: 
+      Silent: "-ms -ma"
+      SilentWithProgress: "-ms -ma"
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