This volume brings together revised versions of a selection of papers presented at the Sixth International Conference on "Recent Advances in Natural Language Processing" (RANLP) held in Borovets, Bulgaria, 27-29 September 2007. These papers cover a wide variety of Natural Language Processing (NLP) topics: ontologies, named entity extraction, translation and transliteration, morphology (derivational and inflectional), part-of-speech tagging, parsing (incremental processing, dependency parsing), semantic role labeling, word sense disambiguation, temporal representations, inference and metaphor, semantic similarity, coreference resolution, clustering (topic modeling, topic tracking), summarization, cross-lingual retrieval, lexical and syntactic resources, multi-modal processing. The aim of this volume is to present new results in NLP based on modern theories and methodologies, making it of interest to researchers in NLP and, more specifically, to those who work in Computational Linguistics, Corpus Linguistics, and Machine Translation.