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CAT Tools

Summary

Computer Assisted Translation (CAT) tools are software applications that help human translators work more efficiently and consistently by providing translation memory, fuzzy matching, glossaries, and other productivity features.

Core Features

Feature Description
Translation Memory (TM) Database of previously translated segments (sentences/paragraphs) that can be reused
Fuzzy Matching Finds similar but not exact matches in TM, showing a percentage score
Keyword Search Searches across TM and glossaries for relevant terms
Glossaries / Term Bases Controlled vocabulary ensuring consistent terminology
Translation Leveraging When source files update, existing translations are preserved and marked for review
File Format Support Handles many formats (.po, .properties, .html, .xml, .docx, .xlsx, .idml, etc.) via format-specific filters
Quality Assurance Tag validation, spell checking, consistency checks

How They Work

  1. Project creation — Translator sets source/target languages, loads source files
  2. Segmentation — Source text is split into segments (usually sentences) using SRX rules
  3. Translation — Translator works segment by segment; TM suggests matches
  4. Compilation — Translated segments are compiled back into the original file format
  5. Leveraging — When source updates, old translations are reused where possible

Open Source vs Commercial

Open Source: - omegaT — Free, GPL v3, Java-based, cross-platform, community-maintained - Strong plugin ecosystem, extensive file format support

Commercial: - SDL Trados Studio — Industry standard, expensive, Windows-only - memoQ — Popular alternative, Windows-only - Wordfast — Cross-platform, freemium model - Smartcat — Cloud-based, freemium

Key Standards

  • TMX (Translation Memory eXchange) — Standard format for exchanging translation memories
  • SRX (Segmentation Rules eXchange) — Standard for sentence segmentation rules
  • TBX (TermBase eXchange) — Standard for terminology exchange
  • XLIFF (XML Localization Interchange File Format) — Standard for localization data exchange

CAT Tools vs Machine Translation

CAT tools assist human translators — they don't translate automatically. Machine Translation (MT) produces automatic translations. Modern CAT tools often integrate MT engines (Google Translate, DeepL) as additional suggestion sources alongside TM matches.