A simple, yet powerful, HTML5 calendar and to-do list
WebCalcium is an open source application which acts as a mix of a calendar and to-do list. You can add events, tag them, add a date; then, using the search tool, you can filter them by the previous paramaters or via full-text search.
Its interface adapts to different screens, from desktop to smartphone, with tablets in the middle. The toolbar will take more or less space according to the width, and the dual pane will be enabled in large enough screens.
[Note on licenses: the code is Apache licensed; it includes jquery, toastr, IndexedDBshim and kalendae (MIT-licensed all of them), and icons are adapted versions of GNOME High-Resolution icons (http://commons.wikimedia.org/wiki/GNOME_High_contrast_icons) , LGPL licensed by its authors (http://commons.wikimedia.org/wiki/GNOME_High_contrast_icons/authors).]