Not all the tools are of same quality and price. NER can be referred to as NER or span labelling or sequence labelling (can be used for POS and other tasks as well)
- https://github.com/chakki-works/doccano - NER, Text Classification, Sequence to Sequence, Text Classification
- https://github.com/heartexlabs/label-studio – NER in Text/HTML, Text Classification, Image Object Detection / Polygons, Audio, etc.
- https://gate.ac.uk - NER, Text Classification
- http://brat.nlplab.org - NER, Relations, Normalization, …etc
- https://prodi.gy - commercial tool, NER, Text Classification
- https://lighttag.io - commercial tool, NER, Relations, Classification
- https://www.tagtog.net – commercial tool, NER, Relations, Classification.
- https://github.com/m8nware/ann - NER, persists to disk, common lisp, basic auth, built-in diffs
- https://github.com/jiesutd/YEDDA - NER annotation, admin interface / comparisons, desktop, python
- https://github.com/emanjavacas/cosycat
- https://github.com/annefried/swan
- https://github.com/tayllan/viper - NER, js based
- https://paperai.github.io/htmlanno - NER, relations, paragraph selection, js based
- https://github.com/aldanor/plato - binary classification, no backend, csv, hotkeys, js based
- https://github.com/paperai/pdfanno - NER / span annotations for pdf
- https://github.com/allenai/pawls - NER / section annotations for pdf with 'preannotation' capability
- http://quepid.com/ - commercial judgement list for relevancy sorting
- https://inception-project.github.io/ – NER, Lemma, Coreference, java based
- http://neuroner.com/ - NER
- https://github.com/CogComp/talen - NER, java
For annotations in jupyter:
- http://www.janfreyberg.com/superintendent - widgets for jupyter notebooks
- https://github.com/natasha/ipyannotate - widgets for jupyter notebooks
Miscelanious:
- https://github.com/Dumbris/trunklucator - backbone for 'roll your own solution' (sample NLP classification) - based on label-studio
- https://pybossa.com - more of 'roll your own solution'
- https://github.com/danvk/localturk - mimicking Mechanical Turk API