iPhone and Mac Developer Program members can now download a preview of Xcode 4, the next generation of Apple's integrated development environment for creating iOS and Mac OS X applications.

With a brand-new interface, compiler, debugger and dozens of new features, Xcode 4 is faster, easier to use, and more helpful than ever before. Quite simply, Xcode 4 will help you writer better code.

Read about the many new enhancements in Xcode 4 and download the developer preview today.

All binary submissions to iTunes Connect must now be uploaded using Application Loader either through Xcode's built-in App Submission process, or directly using the Application Loader software. This offers a significantly improved experience over uploading through iTunes Connect, including faster uploading, a more stable connection, and early validation warnings. Make sure the status of your app in iTunes Connect is Waiting for Upload before you submit your binary.

Read the Distributing Applications section of the iOS Development Guide for more information about preparing your app for submission to iTunes Connect.

Registered Apple Developers can also download and watch these session videos from WWDC 2010 to learn more about using Application Loader for binary submission:

• App Publishing with iTunes Connect
• Mastering Xcode for iPhone OS Development, Part I

The new iAd for Developers program is a great way for you to advertise your own apps to millions of users across the iAd Network. When a user taps on an ad for your app, they can download it from the App Store without leaving the app they're in.

It's easy to get started. Learn more about how you can drive more customers to your app with iAd for Developers.

iTunes Connect now offers exciting new features and enhancements. The iTunes Connect Developer Guide (version 6.0) provides details about these features and how you can take advantage of them, including:

• Using the new Version Release Control to choose when your new app version goes live on the App Store;
• Delivering binaries using Application Loader;
• New states for your app including Prepare for Upload, Pending Developer Release, and Processing for App Store;
• UI Enhancements that indicate when you can edit your app information;
• Game Center functionality for the setup of Achievements and Leaderboard Categories for sandbox testing purposes.

You'll find the iTunes Connect Developer Guide available for download on the homepage of iTunes Connect.

The iTunes Connect Mobile (iTC Mobile) app for iPhone allows you to review your sales and related trends, and make informed business decisions while you're on the go. You can also view your aggregated unit sales information by product line (e.g., paid apps, free apps, In-App purchases), market (e.g., U.S., France) and individual product. Your information is displayed graphically and can be customized to view select periods of time.

The iTC Mobile app for iPhone is available as a free download from the App Store. For detailed instructions on how to take advantage of all the features of iTC Mobile, download the iTC Mobile User Guide from the homepage of iTunes Connect.

Take full advantage of the Retina display on iPhone 4 by uploading a hi-res small app icon and hi-res screenshots for your apps in iTunes Connect. Read the Technical Q&A: App Icons on iPad and iPhone and review the Upload section of the iTunes Connect Developer Guide for more details.

The latest version of the iTunes Connect Developer Guide (version 5.6) is now available. This new version includes information on:

• Enabling your app for iAd rich media ads and the iAd Network module in iTunes Connect;
• New support for requesting Promotional Codes;
• Fetching crash logs on demand;
• Requirements for submitting high resolution screenshots and small icons.

You'll find the iTunes Connect Developer Guide available for download on the homepage of iTunes Connect.

The initial launch of iAd rich media ads, featuring advertising from some of the world's leading brands, will begin July 1.

At launch, we’ll roll out in North America and ramp up the number of ads served in the weeks and months ahead. For developers outside of North America, iAd will be rolled out in a few months.

If you haven’t already joined the iAd Network, visit the App Store Resource Center for details on getting started.

Read the Working with Banner Views section of the iAd Programming Guide for details on using the bannerView:didFailToReceiveAdWithError: method so that your banner view responds correctly when advertisements are not available. Registered Apple Developers can also watch the WWDC 2010 session video Integrating with iAd, which covers ad banner events in the Application Frameworks section of the presentation.

The next generation of the world's most advanced mobile operating system is in the hands of iPhone users around the world, and is now available to iPod touch users for free.

Make sure that your applications are compatible with iOS 4. All new applications and updates to existing applications must be built with iPhone SDK 4. In addition, the App Store will no longer support applications that target iOS 2.x.

Review the iOS 4 Readiness Checklist for a wealth of technical resources to help you make the most of the new technologies in iOS 4 and information on submitting your iOS 4 apps to the App Store.

Everything from the way you describe the functionality of your app to the images you use for your screenshots will impact a customer's initial perception of your app. Here are a few tips that can help you create a great presence for your app on the App Store:

• Write your Application Description with a focus on what makes the functionality or design of your app unique.
• Use engaging screenshots that demonstrate the special capabilities of your application.
• Keep your application icons free of terms like "sale," "lite," or "free."
• Make sure your screenshots and application descriptions do not include objectionable material or irrelevant content.
• Leave out specific information about the price of your app in your Application Description.

Consider these tips the next time you upload metadata for your iPad, iPhone, and iPod touch applications.

Make sure your customers know that your iPad, iPhone and iPod touch applications are available on the App Store. Members of the iPhone Developer Program can take advantage of "Available on the App Store" badges and product images of iPad, iPhone and iPod touch for marketing and advertising. Log in to the App Store Resource Center to download these images, make sure you review the App Marketing and Identity Guidelines for Developers to ensure you use all artwork correctly.

Log in to iTunes Connect and submit your iOS 4 application now, so it will be ready for sale when iOS 4 is available to iPhone and iPod touch users. Make sure you have built and tested your app using iOS 4 and iPhone SDK 4 GM seed available from the iPhone Dev Center.

The iAd Network offers you a new, easy-to-implement source of revenue through incorporating iAd rich media ads in your applications. Apple sells and serves the ads, and you receive 60 percent of the advertising revenue. Learn about getting started with the iAd Network, how to prepare your apps for iAd, and how to create iAd rich media ads.

We are pleased to announce the Safari Developer Program. This free program provides you with the tools and resources you need to create extensions that enhance and customize Safari. You can add buttons to the Safari toolbar, create bars of your own, modify the behavior and appearance of webpages, and more - all with HTML5, CSS3, and JavaScript.