= Welcome to kahina.org =

For imperative programming languages like C or Java there exist comfortable debuggers that visualize the execution of programs in much detail and dramatically ease searching for bugs. For logic programming languages like Prolog, such graphical tools are hardly available. The aim of our project is to develop a graphical debugger that visualizes the complex processes in executing logic programs using a novel, intuitive graphical depiction as multidimensional trees.

Our first use case is the development of unification-based grammars. Those are mathematically precise models of natural language assigning words and sentences syntactic structure and meaning representations. Using software like the [http://www.sfs.uni-tuebingen.de/hpsg/archive/projects/trale/ TRALE] system, they can be implemented as logic programs and tested. Since the analysis (parsing) of even short sentences can easily comprise several thousand programming steps, there is an urgent need for a graphical debugger that makes parsing processes more easily traceable.

We want Kahina to not only fill this gap, but also, with a little configuration, serve as a debugger for other systems in grammar development and logic programming.

= Kahina Facts =

 * Kahina is published under the [http://www.gnu.org/licenses/gpl.html GNU General Public License v3].
 * Kahina's precursor [http://code.google.com/p/trale-sld trale-sld] is a working prototype and available at Google Code.
 * The name ''Kahina'', with emphasis on the first syllable, is Finnish for ''rustle'', a metaphor that lends itself well to describing the visual dynamics of Kahina's multidimensional control flow tree. More often, the word occurs in the sense of ''quarrel'', evoking the picture of a logic programmer wrestling with control structure.
 * Kahina is being developed by Johannes Dellert and [http://kilian.evang.name Kilian Evang] with the help and supervision of [http://www.sfs.uni-tuebingen.de/~fr Frank Richter] of the [http://www.sfs.uni-tuebingen.de/en/index.shtml Department of Linguistics] at [http://www.uni-tuebingen.de/en/landingpage.html Universität Tübingen]. It is funded by the [http://www.mfg.de/ MFG Medien- und Filmgesellschaft Baden-Württemberg] through a [http://www.karl-steinbuch-stipendium.de/ Karl-Steinbuch-Stipendium]. The preliminary Kahina logo is based on [http://www.flickr.com/photos/grantmac/492403688/ Spring leaves] by [http://www.flickr.com/photos/grantmac/ Grant MacDonald].

= Developers' Resources =

 * [http://kahina.org/svn Subversion repository]
 * [http://kahina.org/javadoc Javadoc], updated automatically from the source code repository
 * There is no hackers' manual yet. If you want to explore on your own how an application in the Kahina framework works, [http://kahina.org/trac/browser/kahina/trunk/src/org/kahina/tralesld/TraleSLDRunner.java org.kahina.tralesld.TraleSLDRunner] is a good starting point. Please note that the API is still subject to, possibly radical, change.
 * [wiki:Schedule] showing our next goals and dates envisaged for completion.
 * [wiki:Plans] in a state in which they are best viewed as a collection of ideas, rather than a set of concrete but isolated tickets