# Interactive Data Language

> programming language

**Wikidata**: [Q1665857](https://www.wikidata.org/wiki/Q1665857)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/IDL_(programming_language))  
**Source**: https://4ort.xyz/entity/interactive-data-language

## Summary
Interactive Data Language (commonly known as IDL) is a proprietary, dynamically typed array programming language first introduced in 1977 for data analysis and scientific use. It supports array-oriented programming and reads and writes Hierarchical Data Format (HDF) files.

## Key Facts
- Inception: 1977.  
- Instance of: programming language and array programming language.  
- License: proprietary license; copyright status: copyrighted.  
- Typing discipline: dynamic typing.  
- Programming paradigm: array programming.  
- Readable and writable file format: Hierarchical Data Format (HDF).  
- Common aliases: "IDL" and "Idl (langage)".  
- Current/preferred version listed: 8.7 (qualifier date 2018-02-19). Other recorded versions: 8.6 (2016-11-28) and 8.2.2.  
- Official website: https://www.harrisgeospatial.com/Software-Technology/IDL.  
- Distinct from "interface description language" (listed as different_from).

## FAQs
### Q: What is IDL used for?
A: IDL is used as an array-oriented programming language for scientific and data analysis tasks, with built-in support for array operations and HDF file I/O.

### Q: Is IDL free or open source?
A: No. IDL is distributed under a proprietary license and its copyright status is listed as copyrighted.

### Q: What is the latest stable version of IDL?
A: The preferred recorded version is 8.7 with a qualifier date of 2018-02-19. Earlier recorded versions include 8.6 (2016-11-28) and 8.2.2.

### Q: What typing discipline does IDL use?
A: IDL uses dynamic typing.

## Why It Matters
Interactive Data Language matters because it provides a long-established, array-focused programming environment tailored to scientific and analytical workflows. Its array programming paradigm simplifies operations on multi-dimensional datasets, which is central to disciplines that process large volumes of numerical data. IDL’s built-in support for Hierarchical Data Format (HDF) enables straightforward reading and writing of common scientific data files. The language’s longevity (inception in 1977) and focused design have made it a recognizable tool in domains that require numeric computation and visualization. Although it is proprietary, IDL remains relevant where array-oriented constructs and direct HDF interoperability are priorities. It is sufficiently well-known to have editor and tooling support (for example, an Emacs package named IDLWAVE) and community presence (e.g., a Stack Overflow tag for the IDL programming language), which helps users integrate it into development and analysis workflows.

## Notable For
- Being an array programming language designed for numerical and scientific data processing.  
- Long history with inception in 1977, indicating decades of use in scientific contexts.  
- Native support for reading and writing Hierarchical Data Format (HDF).  
- Distributed under a proprietary license and maintained in multiple versions (notably 8.6 and preferred 8.7).  
- Tooling and community references, including an Emacs package (IDLWAVE) and a Stack Overflow tag.

## Body

### Overview
- Name: Interactive Data Language (commonly "IDL").  
- Classification: programming language; specifically an array programming language.  
- Primary use context: science (listed use value).

### History and Identification
- Inception year: 1977.  
- Freebase identifier: /m/02k681 (reference publication date 2013-10-28).  
- FOLDOC entry: Interactive+Data+Language.  
- Wikipedia title reference: "IDL (programming language)".  
- Sitelink count: 15; available Wikipedia language links include commons, de, en, fi, fr, hr, hu, it, ja, ko.

### Versions and Release References
- Version entries recorded:  
  - 8.2.2 (value recorded).  
  - 8.6 with qualifier date 2016-11-28 (reference: Harris Geospatial release notes).  
  - 8.7 marked as preferred with qualifier date 2018-02-19 (reference: Harris Geospatial release notes).

### Technical Characteristics
- Typing discipline: dynamic typing.  
- Programming paradigm: array programming.  
- Readable file format: Hierarchical Data Format (HDF).  
- Writable file format: Hierarchical Data Format (HDF).

### Licensing and Copyright
- License: proprietary license.  
- Copyright status: copyrighted.

### Related Software and Community
- IDLWAVE: an Emacs package that supports editing IDL source code and running IDL as an inferior shell (inception: 1999).  
- Perl Data Language: listed as a related set of free software array programming extensions to Perl (inception: 1996).  
- Community tagging: Stack Overflow tag available at https://stackoverflow.com/tags/idl-programming-language.

### Distinctions and Disambiguation
- Explicitly listed as different from "interface description language" to avoid name confusion.

### Links and Resources
- Official website: https://www.harrisgeospatial.com/Software-Technology/IDL.  
- Further identifiers: foldoc_id "Interactive+Data+Language"; freebase id /m/02k681.

## References

1. [Source](http://www.harrisgeospatial.com/Support/Maintenance/TabId/2350/ArtMID/10427/ArticleID/15161/Whats-New-in-IDL-86.aspx)
2. [Source](http://www.harrisgeospatial.com/Support/MaintenanceDetail/TabId/3428/ArtMID/13350/ArticleID/22338/IDL-87-Release-Notes.aspx)
3. Freebase Data Dumps. 2013