2.  Java  Python  Bigtable(Bt) is a distributed storage system for managing structured data that is designed to scale to a very large size.  Query Language is GQL

3.  Java Data Objects (JDO)  Java Persistence API (JPA  Java Server Faces (JSF) 1.1 - 2.0  Java Server Pages (JSP) + JSTL  Java Servlet API 2.4  JavaBeans™ Activation Framework (JAF)  Java Architecture for XML Binding (JAXB)  JavaMail  XML processing APIs including DOM, SAX, and XSLT

4.  Enterprise Java Beans (EJB)  JAX-RPC  JAX-WS  Java Database Connectivity (JDBC)  Java EE™ Connector Architecture (JCA)  Java Management Extensions (JMX)  Java Message Service (JMS)  Java Naming and Directory Interface (JNDI)  Remote Method Invocation (RMI)

5.  Write to the filesystem.  Open a socket or access another host directly.  spawn a sub-process or thread.  Applications must use the App Engine datastore for storing persistent data.  A web request to an application must be handled in a single process within a few seconds.  Processes that take a very long time to respond are terminated to avoid overloading the web server.

6.  It supports  Flash  Ajax  APIS  Let us see an example  Shujaathussain.appspot.com  Guestnust.appaspot.com

7.  An app can use the Mail service to send email messages on behalf of the application's administrators, or on behalf of the currently signed in user. Java apps use the JavaMail interface for sending email messages.  The App Engine Memcache provides fast, transient distributed storage for caching the results of datastore queries and calculations. The Java interface implements JCache

8.  The Images service lets applications transform and manipulate image data in several formats, including cropping, rotating, resizing, and photo color enhancement.  Apps use the URL Fetch service to access resources over the web, and to communicate with other hosts using the HTTP and HTTPS protocols. Java apps can simply use java.net.URLConnection and related classes from the Java standard library to access this service.

9.  An application can use Google Accounts for user authentication.  Apps can use the App Engine Datastore for reliable, scalable persistent storage of data. The datastore supports 2 standard Java interfaces: Java Data Objects (JDO) 2.3 and Java Persistence API (JPA) 1.0. These interfaces are implemented using DataNucleus Access Platform, the open source implementation of these standards.