Can anyone point me to write ups of Siri's implementation and history? I know Siri was previously a product on the iPhone, so I'm wondering what company created

Can anyone point me to write ups of Siri's implementation and history? I know Siri was previously a product on the iPhone, so I'm wondering what company created the the technology, and if they perhaps had a more open attitude in discussing their technology than we might hear from Apple and whether they might have some blog posts to look through, etc.