Developing Apps for Office represents a massive opportunity! Your apps can reach over 1 billion Office users and lovers around the world!
We showed a glimpse of what's possible at Build 2015 when we showed the world how Uber and DocuSign were able to use Office API's to bring their services into Office. Office API's let you:
Extend Office Everywhere
Build apps that extend the familiar Office and Office 365 experience across desktop, web, and mobile platforms.
Surface your services and data in the most widely-used productivity platform on the planet.
Sell your apps in 147 international markets or deploy to your organization.
Connect to Office 365 Services
Build custom solutions across all mobile, web and desktop platforms that connect to Office 365.
Connect securely to Office 365 APIs to access email, files, calendar, and people information, and the petabytes of data that are stored there.
Use industry open standards such as OAuth and OData.
Build using an Open Platform
Use Visual Studio or the IDE of your choice.
Host your apps in Microsoft Azure or the cloud platform of your choice.
If you are interested in developing apps for Office and tapping into this 1 billion+ opportunity then head to Office Dev Center for more details: http://dev.office.com/getting-started