The Office Web Apps is the Word, PowerPoint, Excel and OneNote engine that allows users to work with Office content using the web browser.
A single server Office Web Apps Server is capable to support users of Exchange Server 2013, Lync Server 2013 and SharePoint Server 2013  viewing files stored on network shares enabling greater server utilization on the existing infrastructure.

The installation of 
Office Web Apps Server must be on a dedicated server. It can't be installed on a existing SharePoint Server. Servers can be added together to form a farm Office Web Apps  to accommodate more connections, improve the user experience and high availability. The following are supported versions of the browser for viewing and editing of documents:
  • Internet Explorer 7 or higher 
  • Safari 4 or later
  • Chrome
  • Firefox 3.5 or higher


The Office Web Apps Server allows users of SharePoint 2013 to view and edit any Office file that are published.
SharePoint implements features such as preview and document sharing via link.

For an On-Primise environment during the creation of Office Web Apps Farm the feature to edit documents can be enabled, but this feature requires a separate license.  Users of SharePoint Online and Office 365 have this feature enabled by default.


With the integration with Exchange 2013 documents sent as an attachment can be viewed in OWA ( Outlook Web Access ) using the preview. But the documents are opened as read only. 
The following extensions are supported in Office Web Apps:

  • Word - doc, docx, dotx, dot, dotm
  • Excel - xls, xlsx, xlsm, xlm, xlsb
  • PowerPoint - ppt, pptx, pps, ppsx, potx, pot, pptm, potm, ppsm

For users of
Exchange Online preview of the feature is available by default.
For users of Exchange 2013 On-Premise it's a mandatory installation of Office Web Apps Server to view the files in OWA. This is a major change compared to Exchange Server 2010 that has the function of web-ready implemented internally, but Exchange 2013 requires the integration of Office Web Apps.

Below I have the prints of an Excel file attached and its visualization in Office Web



The Lync Server 2013 uses the Office Web Apps to share PowerPoint presentations. Using Office Web Apps users have the best experience of transition between slides and animations and support of audio/video stream.
The presentations utilize DHTML and JavaScript standards for the broadcast, allowing support for mobile devices viewing. Below I have a print of a presentation shared between two users.

Online Viewers

The Viewers Online is a feature of Office Web Apps that allows you to view files that are stored on file servers or published on other web sites.

When this feature is enabled a separate portal on Office Web Apps Server is made available to create the access link for the documents

Below I have the print portal to generate the link to the file

Below I have an Excel file that is stored on my file server

This article was originally written by:
Fernando Lugão Veltem
blog:  http://flugaoveltem.blogspot.com/  
twitter:  @ flugaoveltem