IEI — Indo-European Isoglosses
IEI (Indo-European Isoglosses) is a database of phonological correspondences across attested Indo-European languages. Its aim is to represent, in an accessible format, the body of knowledge on regular Indo-European sound correspondences.
For each reconstructed Proto-Indo-European phoneme, the database records its reflexes in the daughter languages. On this basis, users can perform queries and visualise the resulting groupings of languages on a geographical map.
This platform is in active development and constitutes an early public release. While its core architecture and main functionalities are operational, the underlying dataset remains under systematic construction and validation. All outputs should therefore be considered provisional: apparent absences or distributions may reflect gaps in data coverage rather than established linguistic evidence. Details of both content and interface are subject to change.
Progress so far
The PIE model selection section is not yet fully operational. It is conceived as a global settings panel for selecting the inventory of Proto-Indo-European phonemes adopted by the user. At present, a comprehensive Classic inventory is selected by default and cannot be modified.
The Attested phonologies section displays the phonemic inventories of a subset of Indo-European languages. Phonemes are arranged in standard phonological grids, with each item linked to its Proto-Indo-European sources. Selecting a phoneme reveals its features and its complete set of PIE ancestors.
The Correspondences section is intended to visualise the full set of PIE → outcome correspondences for a given language as an interactive three-level graph.
The Isogloss Explorer allows the user to construct a query visually and to display the resulting geographical distribution across the Indo-European family on a map.
History
- May 2026: first public release (early access); the platform is under active development and data coverage is being continuously expanded. Feedback is welcome (artemij.keidan@uniroma1.it).
- 2015–2026: initial development phase and first data entry.
Settings
PIE Consonants
PIE Vowels
Consonants
Vowels
Correspondence Vectors
Red = languages matching the isogloss. Grey = languages not matching.
Query builder
Query in JSON format
{ }
Actions
Results
No active query.
Blog
Notes and essays tagged #IEI from Śabdānuśāsana.
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Credits
| Conception and design |
Artemij Keidan (opens in new tab) Italian Institute of Oriental Studies, Sapienza University of Rome artemij.keidan@uniroma1.it |
|---|---|
| Data curation |
Artemij Keidan Alessandro del Tomba Andrea Di Manno All data are manually collected, curated, and annotated. |
| Technical development |
Original implementation by Daniel Beilinson (opens in new tab). Subsequent development and extensions were carried out with the assistance of AI-based programming tools (Claude, Anthropic). |
| External libraries |
D3.js (opens in new tab) (version 7) Open-source JavaScript library for data-driven and interactive visualisation. TopoJSON Client (opens in new tab) (version 3) JavaScript module for manipulating topological geospatial data. |
| Funding |
Sapienza University of Rome The initial development phase was supported by a Sapienza University Research Office Grant (project title: Indo-European isoglosses: data collection and models of representation). |
| Copyright and licensing |
© 2015–2026 Artemij Keidan All rights reserved. The database and its contents may not be reproduced, distributed, or reused without explicit permission. |