Inkling recently announced their HTML5-powered web app. The company specializes in making digital textbooks for iPad, and until now these books were only available for iPad through the native app. However, you can now access it through the web on any computer with a compatible browser.
They say that the application, Inkling for Web, does not require Flash or any other such plugins. All of their current titles are available through the web app, and they plan on releasing all of their future eBooks in the format as well.
Check out their eBooks here.