I use Active Calculus by Matt Boelkins et al, and like it a lot. It is very good and totally open source (the author provided me the LaTeX files, which are licensed under Creative Commons, so that I could modify at will!) I also use and like (though they are less traditionally structured calculus texts, but in a way this is one of their strong points) the Calculus in Context series. For online homework I use Webwork from MAA, which is free and open source - you can even write your own problems and contribute them to a national database. More generally, I tend to use AIM's Open Textbook Initiative to find open source texts. I've had very good experiences with the texts I have found. (PS sorry I can't post links to everything I mention here - I don't have enough rep points yet!)

I use Active Calculus by Matt Boelkins et al, and like it a lot. It is very good and totally open source (the author provided me the LaTeX files, which are licensed under Creative Commons, so that I could modify at will!) I also use and like (though they are less traditionally structured calculus texts, but in a way this is one of their strong points) the Calculus in Context series. For online homework I use Webwork from MAA, which is free and open source - you can even write your own problems and contribute them to a national database. More generally, I tend to use AIM's Open Textbook Initiative to find open source texts. I've had very good experiences with the texts I have found.