EWS client libraries
EWS is the primary API for access information stored on Exchange Online, Exchange Online as part of Office 365, and on-premise versions of Exchange starting with Exchange 2007. EWS is a SOAP-based web service. The XML exposed by EWS is rather complex so Microsoft and some third-party developers have created client object models for using EWS. This curation contains links to some of the client object models available for EWS.
29 Apr 2014
Microsoft Exchange Web Services Managed API 2.0
A .Net API for EWS. This is the .Net API provided by Microsoft to access Exchange data with EWS.
EWS Java API 1.2
A Java implementation of the EWS Managed API. This object model has support for the Exchange schemas up to Exchange2010_SP2.
JWebServices for Exchange - Java EWS API
A Java API for EWS. Appears to be very current in its support of EWS up through Exchange 2013 and Exchange Online. API description contains a very detailed list of features and includes many features that are not implemented in the EWS Managed API. It also supports Android.
EWSJ and EWSJ for Android
A Java API for EWS. Implements many of the core EWS features.
A PHP API for EWS. This project appears to be maintained by a community.
EWSWrapper Homepage » Talk to Microsoft EWS effortlessly via PHP or Python
A PHP and Python client for EWS. This project doesn't appear to be active.
suds-ews Python client
A Python client for EWS. This project doesn't appear to be active.
Exchange Web Services .NET - EWS API
A .Net API for EWS. Appears to be very current in its support of EWS up through Exchange 2013 and Exchange Online. API description contains a very detailed list of features and includes some features that are not implemented in the EWS Managed API.
Office 365 SDK for Android on GitHub
I haven't tried this yet but am excited to see this now available. Here's more info on this client. http://msopentech.com/blog/2014/03/03/new-open-source-sdk-for-android-brings-office-365-apps-to-life/