Lightning is a calendar application which works with the popular Mozilla Thunderbird and SeaMonkey mail clients. It lets you manage multiple calendars, create your daily todo list, invite friends to events, and subscribe to public calendars.
CalDavZAP is a CalDAV Web client with a powerful event/todo editor. It is compatible with Safari/Mobile Safari, Webkit, Epiphany, iCab, Chrome, and Firefox, and supports all major CalDAV servers.
A Lisp-like, general-purpose scripting language.
A Firefox add-on that adds a search engine that donates 80% of its income for tree planting.