Searching XKCD. Image: DuckDuckGo.

DuckDuckGo already offers quite a few of what the company refers to as goodies — quick answers and clever shortcuts for common search tasks. For example type “1 + 1″ in DuckDuckGo’s search field and you’ll get “1 + 1 = 2″ in addition to your search results. Other goodies include time based queries, unit conversions, facts (for example the weight of a penny and of course DuckDuckGo’s “!bang” syntax for searching specific websites). For a full list of all the built in goodies, see DuckDuckGo.

DuckDuckHack takes the goodies concept and crowdsources it. Now anyone can write a custom plugin for DuckDuckGo and everyone can take advantage of it. There is already a number of cool plugins available, including the XKCD comic search pictured above, as well as more generally useful tools like lyrics search, a Twitter username search or an em-to-pixel converter for web developers.

Anyone can build DuckDuckHack plugins and the idea is for developers to build tools that they personally care about — scratch your own itch and pass it along so everyone benefits. For more info on how to write a plugin (DuckDuckHack plugins are written in a variety of languages depending on the type of search), check out the tutorial and guidelines for developers. DuckDuckHack takes requests as well. If you’ve got an idea for a search shortcut, you can let developers know.

While the new DuckDuckHack plugins idea makes DuckDuckGo an even more compelling Google alternative, some of DuckDuckHack is still a bit rough around the edges and it’s unclear what DuckDuckGo plans to do if two developers build two plugins that conflict by both responding to the same keyword trigger.

Still, DuckDuckHack is only a day old and already it’s added several useful new tools to DuckDuckGo. To learn more about the new plugin search features already a part of DuckDuckGo, visit the DuckDuckGo goodies page.