Poliqarp

Poliqarp is an open source search engine designed to process text corpora, among others the National Corpus of Polish created at the Institute of Computer Science, Polish Academy of Sciences.

Features

Custom query language
Two-level regular expressions:
- operating at the level of characters in words
- operating at the level of words in statements/paragraphs
Good performance
Compact corpus representation (compared to similar projects)
Portability across operating systems: Linux/BSD/Win32
Lack of portability across endianness (current release works only on little endian devices)

↑ "Poliqarp search engine for NKJP data". nkjp.pl. Retrieved 1 December 2020.
↑ "Poliqarp 1.1". nlp.ipipan.waw.pl. Retrieved 1 December 2020.
↑ Janus, Daniel; Przepiórkowski, Adam (25 June 2007). "Poliqarp: an open source corpus indexer and search engine with syntactic extensions". Proceedings of the 45th Annual Meeting of the ACL on Interactive Poster and Demonstration Sessions. Association for Computational Linguistics: 85–88. Retrieved 1 December 2020.