Provide typescript definitions for outlook, excel, word and powerpoint.
There are some available from 3rd parties but these are unsupported and well out of date.
Office Extensibility Team
Bob Fankston commented
I'm glad to see the definition files. Would be nice to have more emphasis on Typescript and Visual Studio integration as in "create office 365 app". Are there any sample apps using Visual Studio as an IDE for Outlook.com or office 365?