Google have launched their Google AdWords API. From their introduction page:

Google's free AdWords API service lets developers engineer computer programs that interact directly with the AdWords server. With the applications created, advertisers and third parties can more efficiently - and creatively - manage their large AdWords accounts and campaigns.

Flexible and Functional
What can you do with the AdWords API? This all depends on your programming genius and clients' advertising needs. Some possibilities might include:

• Generating automatic keyword, ad text, URL, and custom reports

• Integrating AdWords data with databases, such as inventory systems
• Developing additional tools and applications to help you manage accounts

It works in many language and its quota limits will be based on the size and spend of your account. You need a My Client Center account to sign up. Here is some of their support questions.

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