Office Web Apps overview (Installed on SharePoint 2010 Products)

 

Applies to: Word Web App Preview, PowerPoint Web App Preview, Excel Online

Topic Last Modified: 2010-06-11

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Microsoft Office Web Apps is the online companion to Office Word, Excel, PowerPoint and OneNote applications that enables users regardless of their location to access documents and edit documents. Users can view, share, and work on documents with others online across personal computers, mobile phones, and the Web. Office Web Apps is available to users through Windows Live and to business customers with Microsoft Office 2010 volume licensing and document management solutions based on Microsoft SharePoint 2010 Products.

Note

An appropriate device, Internet connection, and supported Internet Explorer, Firefox, or Safari browser are required. Some mobile functionality requires Office Mobile 2010, which is not included in Office 2010 applications, suites, or Web Apps. There are some differences between the features of Office Web Apps, Office Mobile 2010 and the Office 2010 applications.

Information provided in this article is intended for IT Pros planning to use Office Web Apps on SharePoint 2010 Products on-premise in their organizations. SharePoint 2010 Products in this article refers to Microsoft SharePoint Server 2010 and Microsoft SharePoint Foundation 2010 unless otherwise noted. New and updated content will be published on a regular basis.

In this article:

  • Office Web Apps versions

  • Integration with SharePoint 2010 Products

  • Understanding the Office Web Apps user experience

  • Understanding Office Web Apps architecture

  • Understanding how Office Web Apps work

  • Planning Office Web Apps in your organization

  • Deploying Office Web Apps in your organization

Office Web Apps versions

Office Web Apps is available to consumers and businesses through:

Windows Live   For consumers and small-business users, Office Web Apps is available on Windows Live as a free service. For more information, see Using Office Web Apps in Windows Live.

On-premises   Business customers licensed for Microsoft Office 2010 through a Volume Licensing program can run Office Web Apps on a server that runs Microsoft SharePoint Foundation 2010 or Microsoft SharePoint Server 2010. Information in this article relates to an on-premises Office Web Apps solution with SharePoint 2010 Products. Office Web Apps can be downloaded from the Microsoft Volume Licensing Service Center.

Integration with SharePoint 2010 Products

Office Web Apps is tightly integrated with SharePoint 2010 Products. When you install Office Web Apps, the Office Web Apps Services are added to the list of SharePoint Services and the Office Web Apps Feature is added to the available SharePoint Features.

Office Web Apps services include the Word Viewing Service, PowerPoint Service, and Excel Calculation Services that are created and run within the context of SharePoint Services.

The Office Web Apps Feature and services integrate with SharePoint's robust enterprise content management capabilities to provide users the ability to access and work on your organization's documents from anywhere using a Web browser.

Understanding the Office Web Apps user experience

Viewing and editing Office documents

Office Web Apps gives users a browser-based viewing and editing experience by providing a representation of an Office document in the browser. When a user clicks on a document stored in a SharePoint document library, the document opens directly in the browser. The document appears in the browser similar to how it appears in the Office client application. The Web app also provides many of the same editing features as an Office client application.

Office Web Apps provides this representation of an Office Word document, PowerPoint presentation, Excel workbook, or OneNote notebook using native browser objects such as HTML, JavaScript, and images. Each document type is handled differently depending on the Office Web Apps services started and whether the Office Web Apps Feature is activated.

A document in the Word Web App, PowerPoint Web App, or Excel Web App can be edited in the browser or can be opened for editing in the associated Office client application. If while viewing or working in a Web app a user clicks the Edit in Browser button on the Home tab of the toolbar, the user can perform light editing tasks in the browser. A notebook in the OneNote Web App can be edited in the browser natively without having to click the Edit in Browser button or it can be opened for editing in the OneNote client application by clicking Open in OneNote.

If while in a Web app a user clicks the Open in Word, Open in PowerPoint, Open in Excel, or Open in OneNote button on the toolbar, the document will open in the associated Office client application if it is installed on the client computer.

Improving the user experience with Silverlight

Silverlight is a free plugin that can provide richer Web experiences for many browsers. The Silverlight plugin is not required to be installed on the client browser to use Office Web Apps. However, having the Silverlight plugin installed on the browser can provide the following benefits:

  • When using the Word Web App on browsers with the Silverlight plugin installed, users can experience faster page loading, improved text fidelity at full zoom, ClearType tuner settings support, and improved accuracy in location of search string instances when using the find on this page feature.

  • When using the PowerPoint Web App on browsers with the Silverlight plugin installed, users can experience faster page loading, animations will appear smoother than without, and presentation slides will scale with the browser window size.

Having Silverlight installed on the client browser does not provide any additional benefits in Excel Web App and OneNote Web App.

For more information about Silverlight, see https://www.microsoft.com/silverlight/.

Configuring the default open behavior for browser enabled documents

SharePoint 2010 Products uses the Default open behavior for browser enabled documents setting to determine how a document is opened when a user clicks on a document in SharePoint. By default, this option is set to open documents in their associated client application. When Office Web Apps is installed, setup will change this setting to open documents in the browser. However, if the Office Web Apps Services and Feature have not been activated, when a user clicks on a document, the user may receive an error message that indicates that the service cannot be found. The error message includes a button that the user clicks to open the document in the associated Office client application.

For information about how to configure the default open behavior setting in SharePoint, see Configure the default open behavior for browser-enabled documents (Office Web Apps).

Understanding Office Web Apps architecture

Office Web Apps is made up of multiple server components that create and provide renditions of Word documents, PowerPoint presentations, Excel workbooks, and OneNote notebooks stored in SharePoint for viewing and editing in a browser. Each Web app uses some or all these server components depending on content type, user changes, and feature activation. Office Web Apps server components include the following:

Services   When you install Office Web Apps on a server, the Word Viewing Service, PowerPoint Service, and Excel Calculation Services are created in SharePoint Services. Each of these services acts as a service instance for each Office Web App on a stand-alone server or a service instance for each Office Web App on each server in a server farm. Only one service instance for each Office Web App can exist on a single server, but multiple service instances can exist for each Office Web App in a server farm. Each service instance provides a location where a service application is run.

The Office Web Apps service applications are middle-tier components that manage requests from the Web front-end components, cache renditions, store, calculate, and render documents for consumption by the Web front-end. Not all of the Office Web Apps have a service application. The OneNote Web App for example enables the user to edit .one documents using only the OneNote.aspx without needing a service application. Each service application operates within a service instance property.

Administrators can load-balance services in a server farm by choosing to run service instances on particular servers and not on others. Load balancing can be especially useful in environments where one kind of Web app might be used more than others. Administrators create and start service instances when they deploy Office Web Apps. The service applications will run in their associated service instances automatically. After Office Web Apps is installed on at least one server and the service applications are running in a service instance, administrators can configure service application settings by using SharePoint Central Administration and by using Windows PowerShell.

Each service uses a service application proxy in the SharePoint service application proxy group. The proxies provide the location of a service instance within the farm and manage sessions between the Web front-end components and the service applications. The Word Viewing service application, PowerPoint service application, and Excel Calculation Services each has service application proxies in the SharePoint service application proxy group.

Worker processes   The Word Viewing service application and the PowerPoint service application uses worker processes to convert documents and presentations into a series of PNG images or into XAML (if Silverlight is installed), and temporarily stores output locally on-disk. Administrators can configure worker process settings to optimize performance by using SharePoint Central Administration and by using Windows PowerShell.

Web front-end components   Office Web Apps includes a series of .ASPX, .ASHX, and JavaScript files that run on the front-end SharePoint servers. These are ASP.NET Web applications that render markup for the browser and respond to and manage client events (state) that run on the server. Office Web Apps also uses a series of handlers that run as part of the Web front-end to support rendering HTML and servicing requests made in JavaScript.

Office Web Apps Cache   Word Web App and the PowerPoint Web App store document renditions in a cache. Renditions in the cache are then used for future requests of a view of the same document. Using the cache can reduce use of too many system resources to create a rendition. When you deploy Office Web Apps, by default the cache is created as a site collection in the SPContentDatabase. Like other site collections, the cache can be moved to another database depending on performance or backup needs. Cache size and expiration period can also be configured depending on usage and performance requirements. Office Web Apps also includes two timer jobs associated with the cache. Managing the cache can be done by using SharePoint Central Administration and by using Windows PowerShell. For more information about how to manage the cache, see Manage the Office Web Apps cache.

Understanding how Office Web Apps work

Each Web app uses some or all of the components described in the previous section to provide a viewable Office document in the browser and an editable document in either the browser or the client application.

Viewing and editing Word documents using the Word Web App

For viewing Word document types, a combination of images, HTML, and Java Script are used to render a document viewable by the user. If Silverlight is installed on the client browser, some images will be displayed using XAML.

When a user clicks on a Word document in SharePoint, and the Default open behavior for browser enabled documents setting in SharePoint is set to open in the browser, WordViewer.aspx will check the Office Web Apps cache to determine whether a rendition of the document is already available.

If a rendition of the document is available in the cache, Word Web App front-end components will display the document in view mode in the browser. If a rendition of the document is not available in the cache, the front-end component will call the Word Viewing service application to render the document. The Word Viewing service application then initializes and manages a worker process to render the document by converting it into a series of PNG images or XAML (if Silverlight is installed). The Word Viewing service application then returns the rendered document to WordViewer.aspx and to the cache. WordViewer.aspx then displays the document in the browser in view mode. The Word Viewing service application can initialize and manage multiple worker processes, each process dedicated to a single session.

If while in view mode, the user clicks the Edit in Browser button on the Microsoft Word Web App toolbar, WordViewer.aspx will navigate to the Word Editor (edit mode). The Word Editor is a Web front-end component that creates the browser based editing surface that enables the user to work on the document without loss of fidelity.

If while in view mode or edit mode the user clicks the Open in Word button on the Microsoft Word Web App toolbar, the document will open in the Word client application, if it is installed on the client computer.

Viewing and editing PowerPoint presentations using the PowerPoint Web App

For viewing PowerPoint presentation types, a combination of images, HTML, and JavaScript is used to render a presentation viewable by the user. If Silverlight is installed on the client browser, some images will be displayed using XAML.

When a user clicks on a PowerPoint presentation in SharePoint, and the Default open behavior for browser enabled documents setting in SharePoint is set to open in the browser, the front-end components will check the Office Web Apps cache to determine whether a rendition of the presentation is already available.

If a rendition of the presentation is available in the cache, PowerPoint Web App front-end components will display the presentation in view mode in the browser. If a rendition of the presentation is not available in the cache, PowerPointFrame.aspx will call the PowerPoint service application to render the presentation. The PowerPoint service application then initializes and manages a worker process to render the document by converting it into a series of PNG images or XAML (if Silverlight is installed). The PowerPoint service application then returns the rendered document to PowerPointFrame.aspx and to the cache. PowerPointFrame.aspx then displays the document in the browser in view mode. The PowerPoint service application can initialize and manage multiple worker processes, each process dedicated to a single editing session.

If while in view mode, the user clicks the Edit in Browser button on the Microsoft PowerPoint Web App toolbar, PowerPointFrame.aspx will move to PowerPoint Editor (edit mode). PowerPoint Editor is a Web front-end component that creates the browser based editing surface that enables the user to work on the document without loss of fidelity. PowerPointFrame.aspx will send updates to the PowerPoint service application which services editing requests, manages a single worker process for each editing session, manages re-rendering, auto saves, and returns the updated rendition to PowerPointFrame.aspx. PowerPointFrame.aspx then displays the updated presentation rendition in the browser.

If while in view mode or edit mode, the user clicks the Open in PowerPoint button on the Microsoft PowerPoint Web App toolbar, the presentation will open in the PowerPoint client application, if it is installed on the client computer.

PowerPoint Broadcast Slide Show presentations using the PowerPoint Web App

When Office Web Apps is installed and the PowerPoint service application is created, the PowerPoint Broadcast Service and a default broadcast site are also created. When a user (presenter) opens a presentation in SharePoint using PowerPoint 2010, the user can then click Broadcast Slide Show on the Slide Show tab to start a Broadcast Slide Show presentation. When the user clicks Broadcast Slide Show, the presentation will automatically be uploaded to the Broadcast site, and the Broadcast Service starts a broadcast session.

The PowerPoint service application will request the presentation from the Broadcast site. The PowerPoint service application then instructs worker processes to convert the presentation into a series of images or XAML (if Silverlight is installed), and temporarily store output locally on disk. The PowerPoint service application then creates an attendee URL and returns the URL and broadcast session information to PowerPointFrame.aspx. PowerPointFrame.aspx then returns the attendee URL to the presenter’s browser; the presenter can then send the URL in e-mail or post the link for attendees.

During the presentation session, PowerPointFrame.aspx determines the presenter's current location in the presentation, retrieves the current slide from the cache, and renders the updated slide in the browser. Attendee browsers poll PowerPoint.aspx once per second to check for updates in the slide show presentation.

Viewing and editing Excel workbooks using the Excel Web App

The Excel Web App uses DHTML and JavaScript to render and enable editing an Excel workbook without the need for downloading ActiveX controls to the browser running on the client computer. The Excel Web App uses Excel Calculation Services to load the workbook, calculate in full fidelity, refresh external data if it is needed, and maintain the session.

When a user clicks on an Excel workbook in SharePoint, and the Default open behavior for browser enabled documents setting in SharePoint is set to open in the browser, the Excel Web App will use the Excel Services Application Web Service Application Proxy to direct calls to and from Excel Calculation Services.

If while in view mode, the user clicks the Edit in Browser button on the Microsoft Excel Web App toolbar, the user can then edit the workbook in the browser. The browser will send updates to the Excel Calculation Services which will service those editing requests and return updated results to the browser.

If while in view mode or edit mode, the user clicks the Open in Excel button on the Microsoft Excel Web App toolbar, the workbook will open in the Excel client application, if it is installed on the client computer.

Viewing and editing OneNote notebooks using the OneNote Web App

The OneNote Web App uses a combination of HTML and JavaScript to create a rendition of a notebook that can be viewed and edited by the user.

When a user clicks on a OneNote notebook in SharePoint, and the Default open behavior for browser enabled documents setting in SharePoint is set to open in the browser, OneNote.aspx will display the notebook in the browser. The user can edit the notebook in the browser.

If the user clicks the Open in OneNote button on the Microsoft OneNote Web App toolbar, the notebook will open in the OneNote client application, if it is installed on the client computer.

Planning Office Web Apps in your organization

How you deploy Office Web Apps will depend on how users in your organization will use the Web apps to view and edit Office documents in your SharePoint environment. Your Office Web Apps deployment will also depend on your SharePoint server configuration and hardware resources.

In smaller organizations, all of the Office Web Apps components can be deployed on a single SharePoint 2010 Products server. Although this kind of solution does have limitations, as your needs change, you can later expand your Office Web Apps and SharePoint solution to a multiple server farm.

For medium and large-scale organizations, you can install Office Web Apps on multiple servers in a SharePoint 2010 Products server farm. You can optimize performance not only for users viewing and editing Office documents using Office Web Apps, but also for other SharePoint services that are running on the same server farm.

For more information about how to plan an Office Web Apps solution for your organization, see Plan Office Web Apps (Installed on SharePoint 2010 Products).

Deploying Office Web Apps in your organization

Deploying Office Web Apps involves three primary phases: Installing Office Web Apps by running setup, activating the services, and then activating the Office Web Apps Feature.

Office Web Apps can be installed on a SharePoint 2010 Products stand-alone server or server farm. When deploying on a server farm, Office Web Apps must be installed on every server in the farm, however, the services do not have to be activated on every server in the farm. You can choose to balance load by activating the Office Web Apps services on particular servers in the farm. You can also optimize performance by configuring the Office Web Apps cache and worker processes to your particular requirements.

For more information about how to deploy Office Web Apps on-premise in your organization, see Deploy Office Web Apps (Installed on SharePoint 2010 Products).

Summary

Information in this article provides an understanding of how Office Web Apps installed on SharePoint 2010 Products work. This information can help you when planning Office Web Apps in your organization. The next step in your on-premises Office Web Apps solution is to plan your SharePoint and Office Web Apps server configuration. For more information, see Plan Office Web Apps (Installed on SharePoint 2010 Products).