diff --git a/manifests/m/Mozilla/FirefoxDeveloperEdition/88.0b9/Mozilla.FirefoxDeveloperEdition.installer.yaml b/manifests/m/Mozilla/FirefoxDeveloperEdition/88.0b9/Mozilla.FirefoxDeveloperEdition.installer.yaml
new file mode 100644
index 000000000..2835c7e80
--- /dev/null
+++ b/manifests/m/Mozilla/FirefoxDeveloperEdition/88.0b9/Mozilla.FirefoxDeveloperEdition.installer.yaml
@@ -0,0 +1,22 @@
+# yaml-language-server: $schema=https://aka.ms/winget-manifest.installer.1.0.0.schema.json
+PackageIdentifier: Mozilla.FirefoxDeveloperEdition
+PackageVersion: 88.0b9
+Installers:
+- Architecture: x64
+  InstallerUrl: https://download-installer.cdn.mozilla.net/pub/devedition/releases/88.0b9/win64/en-US/Firefox%20Setup%2088.0b9.msi
+  InstallerSha256: 4AB3A4CC63EFE50430E215268C7A6AF5084CFCC0DB981F19519C45DEB1E5156D
+  InstallerType: msi
+- Architecture: x86
+  InstallerUrl: https://download-installer.cdn.mozilla.net/pub/devedition/releases/88.0b9/win32/en-US/Firefox%20Setup%2088.0b9.msi
+  InstallerSha256: 0B5E7129015F1420BBFA4A55AD622478399EE97263EB5DAAF0BB90DDAB6B3A38
+  InstallerType: msi
+- Architecture: arm64
+  InstallerUrl: https://download-installer.cdn.mozilla.net/pub/devedition/releases/88.0b9/win64-aarch64/en-US/Firefox%20Setup%2088.0b9.exe
+  InstallerSha256: 3F2B3C48A4118D352AAA1B71DC1ED77D8FAAB27D789535F4739C0846AB868753
+  InstallerType: exe
+  InstallerSwitches:
+    Silent: /S
+    SilentWithProgress: /S
+ManifestType: installer
+ManifestVersion: 1.0.0
+
diff --git a/manifests/m/Mozilla/FirefoxDeveloperEdition/88.0b9/Mozilla.FirefoxDeveloperEdition.locale.en-US.yaml b/manifests/m/Mozilla/FirefoxDeveloperEdition/88.0b9/Mozilla.FirefoxDeveloperEdition.locale.en-US.yaml
new file mode 100644
index 000000000..36984bdd7
--- /dev/null
+++ b/manifests/m/Mozilla/FirefoxDeveloperEdition/88.0b9/Mozilla.FirefoxDeveloperEdition.locale.en-US.yaml
@@ -0,0 +1,19 @@
+# yaml-language-server: $schema=https://aka.ms/winget-manifest.defaultlocale.1.0.0.schema.json
+PackageIdentifier: Mozilla.FirefoxDeveloperEdition
+PackageVersion: 88.0b9
+PackageLocale: en-US
+LicenseUrl: https://www.mozilla.org/en-US/MPL/2.0/
+Moniker: firefoxdev
+Tags:
+- browser
+- mozilla
+- firefox
+- dev
+PackageUrl: https://www.mozilla.org/en-US/firefox/developer/
+Publisher: Mozilla
+PackageName: Firefox Developer Edition
+License: Mozilla Public License V2.0
+ShortDescription: Firefox Developer Edition is the blazing fast browser that offers cutting edge developer tools and latest features like CSS Grid support and framework debugging.
+ManifestType: defaultLocale
+ManifestVersion: 1.0.0
+
diff --git a/manifests/m/Mozilla/FirefoxDeveloperEdition/88.0b9/Mozilla.FirefoxDeveloperEdition.yaml b/manifests/m/Mozilla/FirefoxDeveloperEdition/88.0b9/Mozilla.FirefoxDeveloperEdition.yaml
new file mode 100644
index 000000000..23e6fc3be
--- /dev/null
+++ b/manifests/m/Mozilla/FirefoxDeveloperEdition/88.0b9/Mozilla.FirefoxDeveloperEdition.yaml
@@ -0,0 +1,7 @@
+# yaml-language-server: $schema=https://aka.ms/winget-manifest.version.1.0.0.schema.json
+PackageIdentifier: Mozilla.FirefoxDeveloperEdition
+PackageVersion: 88.0b9
+DefaultLocale: en-US
+ManifestType: version
+ManifestVersion: 1.0.0
+