The document discusses various cross-platform mobile application development frameworks including Titanium, PhoneGap, Rhodes, Sencha Touch, jQuery Mobile. It notes that over 5000 developers used HTML5 for app development in 2012 according to a survey. The frameworks allow writing apps using a single codebase that can run on multiple platforms like iOS and Android. However, cross-platform apps may have limited access to device-specific features and slower performance compared to native apps. The document also covers pros and cons of cross-platform app development.