DELPH-IN members share a commitment to re-usable, multi-purpose resources and active exchange. Based on contributions from several members and joint development over many years, an open-source repository of software and linguistic resources has been created that has wide usage in education, research, and application building.
At the core of the DELPH-IN repository is agreement among partners on a shared set of linguistic assumptions (grounded in Head-Driven Phrase Structure Grammar and Minimal Recursion Semantics) and on a common formalism (i.e. logic) for linguistic description in typed feature structures. The formalism is implemented in several development and processing environments (that can serve differing purposes) and enables the exchange of grammars and lexicons across platforms. Formalism continuity, on the other hand, has allowed DELPH-IN researchers to develop several comprehensive, wide-coverage grammars of diverse languages that can be processed by a variety of software tools.
Over time, the following configuration of core components has emerged as a typical grammar engineering configuration that is commonly used both by DELPH-IN members and other research initiatives.
- provides an interactive grammar development environment for typed feature structure grammars. The LKB includes a parser and generator, visualization tools for all relevant data structures (including trees, feature structures, MRSs, hierarchies, parse and generation charts), and a set of specialized debugging facilities (like ‘interactive unification’) and well-formedness tests for grammar and lexicon.
- The LKB is implemented in ANSI Common-Lisp and available in full source code or as precompiled binaries for common platforms, including Linux, Solaris, and MS Windows.
- for the high-efficiency processing of typed feature structure grammars complements the LKB as a run-time and application delivery component. PET interprets the same logical formalism (in fact reads the exact same grammar source files) and provides a parser that is (much) less resource-demanding than the LKB, more robust, portable, and available as a library that can be embedded into NLP applications. Unlike the LKB, PET includes only very limited debugging facilities.
- The PET System is implemented in ANSI C++ (with critical parts in pure ANSI C to improve run-time efficiency) and has been ported to several Unix flavours and MS Windows. Its industrial-strength code quality has already been confirmed in a commercial product built on top of PET. Full source code and pre-compiled binaries for (currently) Linux are available.
- The [incr tsdb()] Competence and Performance Profiler provides an evaluation and benchmarking tool to grammar writers and system developers alike. [incr tsdb()] (‘tee ess dee bee plus plus’) acts like an umbrella application to a range of processing systems for typed feature structure grammars, including the LKB and PET, and defines a common format for the organization of test suites or corpora and the storage of precise and fine-grained measures of grammar and processor behavior. [incr tsdb()] profiles abstract over the idiosyncrasies of individual platforms and, thus, facilitate contrastive cross-platform comparison as well as in-depth analysis.
- The [incr tsdb()] environment is implemented in ANSI C (for a simple DBMS), ANSI Common-Lisp (core functionality), and Tcl/Tk (GUI) and has been used successfully in various Un*x flavours. Besides a distribution in full source-code, pre-compiled object files are available that can be loaded on top of common LKB run-time binaries.