gistfile1.txt

en
nltk
http://snowball.tartarus.org/algorithms/porter/stemmer.html
http://snowball.tartarus.org/algorithms/english/stemmer.html
http://proiot.ru/jssnowball/ (online), source https://github.com/mazko/jssnowball
porter stemmer (много на гитхабе)

ru
nltk
http://snowball.tartarus.org/algorithms/russian/stemmer.html
https://github.com/neonxp/Stemmer
https://metacpan.org/pod/Lingua::Stem::Ru
http://proiot.ru/jssnowball/ (online), source https://github.com/mazko/jssnowball

de
nltk
http://snowball.tartarus.org/algorithms/german/stemmer.html
http://snowball.tartarus.org/algorithms/german2/stemmer.html

cs	Czech
http://snowball.tartarus.org/otherapps/oregan/czech-do.sbl
https://github.com/dundalek/czech-stemmer
http://research.variancia.com/czech_stemmer/
http://proiot.ru/jssnowball/ (online), source https://github.com/mazko/jssnowball

be	Belarusian
https://tt-api.tech/en/stemmer (платное)

uk	Ukranian
https://github.com/Amice13/ukr_stemmer
https://github.com/vgrichina/ukrainian-stemmer
https://tt-api.tech/en/stemmer (платное)

pl	Polish
https://pypi.org/project/pystempel/
https://github.com/eugeniashurko/polish-stem
http://www.cs.put.poznan.pl/dweiss/xml/projects/lametyzator/index.xml?lang=en

bg	Bulgarian
https://github.com/gkostadinov/py-bulgarian-stemmer
https://github.com/Glamdring/bg-stemmer

hr	Croatian
http://nlp.ffzg.hr/resources/tools/stemmer-for-croatian/ (обрати внимание, тут гнездо nlp-кодеров про Хорватский)
https://eliteinformatiker.de/2015/05/15/rewriting-university-of-zagrebs-croatian-stemmer-to-a-nltk-compliant-class
https://pypi.org/project/text-hr/
https://vukbatanovic.github.io/SCStemmers/

id	Indonesian
https://snowballstem.org/algorithms/indonesian/stemmer.html
https://pypi.org/project/Sastrawi/
https://github.com/har07/PySastrawi

mk	Macedonian
https://dighumlab.org/cst-lemmatiser/ + https://nlpweb01.nors.ku.dk/download/cstlemma/macedonian/

sk	Slovak
https://github.com/mrshu/stemm-sk
https://github.com/essential-data/stemmer-sk

sl	Slovenian
https://repo.ijs.si/DIS-AGENTS/snowball-stemmer
https://stackoverflow.com/questions/8714040/slovenian-stemmer-for-sphinx (не уверен, что это живое)
http://proiot.ru/jssnowball/ (online), source https://github.com/mazko/jssnowball

sr	Serbian
https://snowballstem.org/algorithms/serbian/stemmer.html
https://vukbatanovic.github.io/SCStemmers/
https://nikolamilosevic86.github.io/SerbianStemmer/
https://github.com/vdragan1993/serbian-stemmer