ABBYY Lingvo .dsl source files, together with abbreviations. The files can be optionally compressed with dictzip. Dictionary resources can be packed together into a .zip file
ABBYY Lingvo .lsa/.dat audio archives. Those can be indexed separately, or be referred to from .dsl files
Support for Wikipedia, Wiktionary, or any other MediaWiki-based sites to perform lookups in
Ability to use arbitrary websites as dictionaries via templated Url patterns. Support for looking up and listening to pronunciations from forvo.com
Hunspell-based morphology system, used for word stemming and spelling suggestions.
Ability to index arbitrary directories with audio files for pronunciation lookups.
Full Unicode case, diacritics, punctuation and whitespace folding. This means the ability to type in words without any accents, correct case, punctuation or spaces (e.g. typing 'Grussen' would yield 'grüßen' in German dictionaries)."