Developers love Engine Yard, the Red Hat for Ruby on Rails. And so do investors, who just plowed another $19 million into the startup, which hosts Ruby-on-Rails deployments.

New investors include DAG Ventures, Bay Partners, and Presidio Ventures. Existing investors Benchmark Capital, New Enterprise Associates, and Amazon also participated. The company had previously raised $15 million in July, 2008 from Amazon and NEA, and $3.5 million from Benchmark the previous January.

Ruby on Rails is a programming framework for Web apps that is fast and easy to deploy. Engine Yard offers a hosted environment for Rails apps that is stable and up to date.