Earlier today Google CEO Larry Page announced that Andy Rubin was stepping down as the head of the Android team, and now the Wall Street Journal has published Rubin's farewell email to the company's Android partners. Describing himself as an "entrepreneur at heart," Rubin writes that he feels it is now the proper time for him to pursue new ventures within Google.

The overall success of Android — he touts the 750 million Android devices in the marketplace — is one of the reasons why Rubin feels now is a suitable time for him to move on. The other, he writes, is the strength of the incoming management team, including both his replacement Sundar Pichai and Android vice president of engineering Hiroshi Lockheimer. The team, Rubin writes, "will work closely with all of our partners to advance Android and prepare the platform for new products and services yet to be imagined."

The former Android chief also takes a moment to call back to the operating system's philosophical roots. "At its core," Rubin writes, "Android has always been about openness — the idea that a thousand brains are better than one." We've included the email in its entirety below.

Dear friends,

In November of 2007 we announced the Open Handset Alliance with 34 founding members. Today, I'm grateful to the over 85 OHA members who have helped us build Android and drive innovation at such an incredible pace. The Android ecosystem has seen tremendous growth since the launch of the very first Android device in October 2008. The volume and variety of Android devices exceeds even my most optimistic expectations - over 750 million compatible devices and counting!

At its core, Android has always been about openness - the idea that a thousand brains are better than one. Just as the ecosystem has grown, so has our team at Google. I am incredibly proud of the phenomenal group of people that spend their days (and nights) building the Android platform and services. Just look at last year...a lean yet incredibly ambitious team released Jellybean with Google Now, launched Google Play in many languages and countries and collaborated with several partners to build three new Nexus devices to help drive innovation in the ecosystem.

Today, the success of Android combined with the strength of our management team, gives me the confidence to step away from Android and hand over the reins. Going forward, Sundar Pichai will lead Android, in addition to his existing work with Chrome and Apps. Hiroshi Lockheimer - who many of you already know well - plus the rest of the Android leadership team will work closely with all of our partners to advance Android and prepare the platform for new products and services yet to be imagined.

As for me, I am an entrepreneur at heart and now is the right time for me to start a new chapter within Google. I am amazed by what we have accomplished from those early days (not so long ago!), and remain passionate about the power of a simple idea and a shared goal - an open source platform freely available to everyone - to transform computing for people everywhere.

Thank you for your support,

- andy