Product Documentation

Citrix App Layering 4

Jan 11, 2018

Welcome to application management simplicity

Citrix App Layering makes it easier to manage your Windows applications. App Layering can help you manage your applications and operating systems regardless of which hypervisor or provisioning service you use.

App Layering separates the management of your operating system and apps from your infrastructure. With App Layering, you can install each of your apps and operating system patches one time, and then use them as part of any image you deploy. You can publish layered images as open standard virtual disks that you can use in any environment. This allows you to maintain a single Windows installation, and a single copy of each application, that you use for all of your images across all of your virtual environments.

  •  App Layering wraps each of your applications in a layer, and stores the layers as virtual disks.
  • You can create any combination of these app layers and an OS layer as part of a layered image, and publish it to your target platform.
  • You can install an application or operating system once, and deploy it as part of any number of images.

Provision servers in any environment

App Layering lets you package any Windows app as a virtual disk, layer and deliver it, installation-free, to session hosts. With App Layering, you can:

  • Install and manage a single copy of your Windows operating system and a single copy of each of your apps in layers.
  • Select any combination of layers to create layered Images that are deployable as session hosts.
  • Deploy those layered images to virtual machine session hosts, making the applications available to users.

You can deliver new applications, application updates, and Windows patches to an entire Remote Desktop Session Host (RDSH) farm with a single image update.

Deliver applications with ease

You can Layer Applications and deliver them as read-only virtual disks, which you can use to:

  • Add the app to one or more Image Templates that you can then use to publish Layered Images and use them to provision session hosts or desktops.
  • Elastically assign apps to users, who will see the apps on their desktops upon login.

Layering is faster and easier than app virtualization and is compatible with more apps. Layers have the look and feel of a local installation and enable full application interoperability.

Each app layer contains the OS layer you want to use for your layers and layered images. It also includes the installed and configured application that is in the state in which you want users to encounter when they log on.

The OS layer is the first layer you create because it is required for creating app layers, platform layers, and image templates. Using the same operating system for all of your layers and images means that you can patch an OS layer once to update it everywhere. For example, after one OS update, you can republish the images for an entire server farm.

Delivering app layers as part of image templates, which are then published as layered images.

Citrix App Layering includes layer platform tools and software to hold infrastructure-related software and settings. You can maintain platform-independent OS and app layers.

Provision RDSH virtual machines. You can create custom RDSH virtual machines by assigning any combination of compatible OS and app layers in any order.

Delivering app layers as elastic layers

You can deliver one of more of your app layers to users as elastic layers that appear on the user's desktop when they log on without restarting. The apps appear to be locally installed even though an installation procedure is not run on the desktop. Elastic layers provide a custom application experience on top of non-persistent virtual desktops (VDI) and Citrix XenApp and RDSH sessions.

Elastic layers are app layers that are elastically assigned to Active Directory Users and Groups.

To use elastic layering, you enable the elastic layering feature for one or more of your image templates. The resulting published layered images support the delivery of elastic layers to users who have logon permissions. The virtual disks that represent elastic layers are mounted based on Active Directory User and Group assignments when users log on.

Based on a patented file system and registry virtualization technology, you can use fewer published desktop and application silos and fewer desktop pools to deliver custom user work spaces. For example, Joe can log on to VMware Horizon Pool 1 and receive his 10 applications. Sally can log on to the same VMware Horizon pool and receive the same 10 applications as Joe and Adobe Acrobat Pro. Likewise, Tom can log on to his Citrix XenApp desktop from Silo 1 and receive 3 applications. Janet can then log in to the exact same XenApp server in Silo 1 and receive the same 3 applications as Tom plus QuickBooks and Microsoft Project.

User (personalization) data and settings (App Layering Labs)

The user (personalization) layer is a feature in App Layering Labs. This layer is writable and includes users local profile changes, user-installed apps and plug-ins, and locally saved data. The user layer supports Windows 7 and Windows 10 OS Layers only. You can deliver fully persistent Windows workspaces by using non-persistent, pooled virtual desktops. You can size your infrastructure based on the maximum number of concurrent users. With this method, you can replace a dedicated virtual machine for every user who needs a persistent experience. You can significantly reduce server and storage costs by using pooled virtual desktops.

A simple addition to your environment

A Citrix App Layering deployment is the App Layering appliance, which is a virtual appliance that you deploy in your environment. The App Layering appliance is also known as the Enterprise Layer Manager. The App Layering appliance hosts the App Layering management console. In the management console you can create layers, and assign them to layered images or directly to users by using elastic assignment.

By using app layering you can create OS, app, and platform layers one time. You then use them to create any number of image templates from which you can publish layered images. You can update the OS, app, or platform software by adding a new version to the layer for each patch or update that you apply.

In app layers, you can deploy virtually any applications compatible with the OS. Each app layer can include one or more applications. When an upgrade to an application is ready, you can add the new version to the layer for the latest update.

Platform layers are designed to support your environment. A platform layer includes your hypervisor tools and settings. The tools and settings make it easy to create layers by using virtual machines in your hypervisor environment. A platform layer that includes your hypervisor, provisioning service, and connection broker software isolates app and OS layers from the infrastructure where they are published.

Layered images for provisioning session hosts and servers

Image templates are where you choose the operating system and layer assignments for an image. You can include OS and app layers in any number of image templates. Using an image template and a platform layer, you can publish layered images to your provisioning service, hypervisor, or network file share.You can publish layered images as virtual disks to any location to which the appliance has access. You can also use the disks to

You can publish layered images as virtual disks to any location to which the appliance has access. You can also use the disks to provision as many servers as you need.


You can configure a connector with the credentials for a specific location in your virtual environment. The configuration allows Citrix App Layering to publish the layered images and provision servers in a specific location. 


For compatibility details, see System Requirements.