# CUE

> data constraint language

**Wikidata**: [Q116962956](https://www.wikidata.org/wiki/Q116962956)  
**Source**: https://4ort.xyz/entity/cue-q116962956

## Summary
CUE is a data constraint language, classified as a type of open-source software. Originally developed by Marcel van Lohuizen and inceptioned in 2018, it functions as a non-tangible executable tool for defining and validating data constraints. The project is actively maintained, with a release history extending from 2021 into 2025, and is distributed under the Apache Software License 2.0.

## Key Facts
- **Entity Type:** Data constraint language; an instance of **software** (the non-tangible executable component of a computer).
- **Inception:** December 2018.
- **Developer:** Marcel van Lohuizen.
- **Maintainer:** Daniel Martí.
- **License:** Apache Software License 2.0.
- **Official Website:** https://cuelang.org/
- **Source Repository:** https://github.com/cue-lang/cue
- **Latest Stable Version:** 0.15.1 (Released November 21, 2025).
- **Package Availability:** Available via MacPorts (port name: `cue`).
- **Software Classification:** As software, CUE is a subclass of creative work, written work, and product.

## FAQs
### Q: What is CUE?
A: CUE is a data constraint language, a specific type of software designed to configure and validate data. It is an open-source tool licensed under Apache 2.0.

### Q: Who created and maintains CUE?
A: The language was developed by Marcel van Lohuizen, with inception in December 2018. It is currently maintained by Daniel Martí.

### Q: When was CUE released?
A: While inceptioned in 2018, the structured release history began in July 2021 with versions 0.0.2 through 0.4.0. It has since evolved through numerous stable releases, reaching version 0.15.1 in November 2025.

### Q: Where can CUE be accessed?
A: The source code is hosted on GitHub at `github.com/cue-lang/cue`, and the official documentation is located at `cuelang.org`. It is also available through the MacPorts system.

## Why It Matters
CUE represents a specialized category of software tools essential for modern computing infrastructure. As a **data constraint language**, it addresses the critical need for reliable data validation and configuration management, serving as a logical tool for computers to perform arithmetic and logical operations on data structures.

Its significance is grounded in its nature as **software**: a creative and written work that acts as a product and a means for system operations. Unlike physical hardware, CUE exists as executable logic, allowing for complex architectural depth and feature extension. By standardizing how data constraints are defined, CUE contributes to the broader field of software engineering, helping to ensure software quality and testability. Its active development cycle, evidenced by frequent updates from 2021 through 2025, highlights its ongoing relevance and adaptation to contemporary technical requirements.

## Notable For
- **Active Development Lifecycle:** Distinguished by a rapid and consistent release cadence, evolving from early alpha versions (0.0.x) to stable releases (0.15.x) within a four-year span.
- **Open Source Licensing:** Utilizes the permissive Apache Software License 2.0, facilitating broad adoption and contribution within the software community.
- **Specialized Utility:** Serves a specific niche as a "data constraint language," differentiating it from general-purpose programming languages like Java or system tools like RandR.
- **Strong Foundations:** Created by Marcel van Lohuizen, aligning the project with experienced software engineering expertise.

## Body
### Definition and Classification
CUE is formally defined as a **data constraint language**. It falls under the superclass of **software**, which constitutes the non-tangible executable component of a computer system. As software, it is characterized as a subclass of creative work, written work, means, and product. It functions as a tool to perform logical operations, distinct from physical hardware.

### Development and Governance
The project was inceptioned on **December 1, 2018**, by **Marcel van Lohuizen**. Development is active and ongoing, with maintenance currently provided by **Daniel Martí**. The project is openly governed via its source repository, allowing for public contribution and transparency.

### Technical Characteristics
CUE is distributed as a digital artifact composed of computer programs and data. Its primary attributes include:
*   **Source Code:** Hosted on GitHub (`https://github.com/cue-lang/cue`).
*   **License:** Governed by the Apache Software License 2.0.
*   **Architecture:** It possesses defined software architecture and quality attributes typical of modern engineering tools.
*   **Distribution:** Binaries and source code are available via the official website and package managers like MacPorts (port: `cue`).

### Release History
The development of CUE is documented through an extensive sequence of version releases, demonstrating a transition from early development to stable production software.

**Early Phase (2021 - 2022)**
The public release history begins in July 2021 with a rapid succession of versions, starting with **0.0.2** through **0.2.2** (all released July 3, 2021). This initial phase concluded with version **0.4.0** on July 3, 2021. Subsequent maintenance releases followed in 2022, including **0.4.1** (Jan 12), **0.4.2** (Feb 4), and **0.4.3** (Apr 21).

**Maturation Phase (2023 - 2024)**
In 2023, the project released version **0.5.0** (Apr 12), followed by the first explicitly labeled "stable" versions: **0.6.0** (Aug 9) and **0.7.0** (Dec 6).
The pace accelerated in 2024 with consistent stable releases:
*   **0.7.1** (Feb 12)
*   **0.8.0** (Mar 15), **0.8.1** (Apr 3), **0.8.2** (Apr 26)
*   **0.9.0** (Jun 6), **0.9.1** (Jun 13), **0.9.2** (Jun 26)
*   **0.10.0** (Aug 15), **0.10.1** (Oct 22)
*   **0.11.0** (Nov 19)

**Recent and Upcoming Phase (2025)**
The release schedule extends into 2025, indicating long-term support and development:
*   **0.11.1** (Dec 18, 2024) and **0.11.2** (Jan 22, 2025)
*   **0.12.0** (Jan 30, 2025) and **0.12.1** (Apr 3, 2025)
*   **0.13.0** (May 22, 2025), **0.13.1** (Jun 10, 2025), **0.13.2** (Jun 24, 2025)
*   **0.14.0** (Aug 1, 2025), **0.14.1** (Aug 11, 2025), **0.14.2** (Oct 10, 2025)
*   **0.15.0** (Nov 6, 2025)
*   **0.15.1** (Nov 21, 2025)

## References

1. [Source](https://mvdan.cc/)
2. [Source](https://api.github.com/repos/cue-lang/cue)
3. [Release 0.0.2. 2021](https://github.com/cue-lang/cue/releases/tag/v0.0.2)
4. [Release 0.0.3. 2021](https://github.com/cue-lang/cue/releases/tag/v0.0.3)
5. [Release 0.0.4. 2021](https://github.com/cue-lang/cue/releases/tag/v0.0.4)
6. [Release 0.0.5. 2021](https://github.com/cue-lang/cue/releases/tag/v0.0.5)
7. [Release 0.0.6. 2021](https://github.com/cue-lang/cue/releases/tag/v0.0.6)
8. [Release 0.0.7. 2021](https://github.com/cue-lang/cue/releases/tag/v0.0.7)
9. [Release 0.0.8. 2021](https://github.com/cue-lang/cue/releases/tag/v0.0.8)
10. [Release 0.0.9. 2021](https://github.com/cue-lang/cue/releases/tag/v0.0.9)
11. [Release 0.0.10. 2021](https://github.com/cue-lang/cue/releases/tag/v0.0.10)
12. [Release 0.0.11. 2021](https://github.com/cue-lang/cue/releases/tag/v0.0.11)
13. [Release 0.0.12. 2021](https://github.com/cue-lang/cue/releases/tag/v0.0.12)
14. [Release 0.0.13. 2021](https://github.com/cue-lang/cue/releases/tag/v0.0.13)
15. [Release 0.0.14. 2021](https://github.com/cue-lang/cue/releases/tag/v0.0.14)
16. [Release 0.0.15. 2021](https://github.com/cue-lang/cue/releases/tag/v0.0.15)
17. [Release 0.1.0. 2021](https://github.com/cue-lang/cue/releases/tag/v0.1.0)
18. [Release 0.1.1. 2021](https://github.com/cue-lang/cue/releases/tag/v0.1.1)
19. [Release 0.1.2. 2021](https://github.com/cue-lang/cue/releases/tag/v0.1.2)
20. [Release 0.2.0. 2021](https://github.com/cue-lang/cue/releases/tag/v0.2.0)
21. [Release 0.2.1. 2021](https://github.com/cue-lang/cue/releases/tag/v0.2.1)
22. [Release 0.2.2. 2021](https://github.com/cue-lang/cue/releases/tag/v0.2.2)
23. [Release 0.3.0. 2021](https://github.com/cue-lang/cue/releases/tag/v0.3.0)
24. [Release 0.3.1. 2021](https://github.com/cue-lang/cue/releases/tag/v0.3.1)
25. [Release 0.3.2. 2021](https://github.com/cue-lang/cue/releases/tag/v0.3.2)
26. [Release 0.4.0. 2021](https://github.com/cue-lang/cue/releases/tag/v0.4.0)
27. [Release 0.4.1. 2022](https://github.com/cue-lang/cue/releases/tag/v0.4.1)
28. [Release 0.4.2. 2022](https://github.com/cue-lang/cue/releases/tag/v0.4.2)
29. [Release 0.4.3. 2022](https://github.com/cue-lang/cue/releases/tag/v0.4.3)
30. [Release 0.5.0. 2023](https://github.com/cue-lang/cue/releases/tag/v0.5.0)
31. [Release 0.6.0. 2023](https://github.com/cue-lang/cue/releases/tag/v0.6.0)
32. [Release 0.7.0. 2023](https://github.com/cue-lang/cue/releases/tag/v0.7.0)
33. [Release 0.7.1. 2024](https://github.com/cue-lang/cue/releases/tag/v0.7.1)
34. [Release 0.8.0. 2024](https://github.com/cue-lang/cue/releases/tag/v0.8.0)
35. [Release 0.8.1. 2024](https://github.com/cue-lang/cue/releases/tag/v0.8.1)
36. [Release 0.8.2. 2024](https://github.com/cue-lang/cue/releases/tag/v0.8.2)
37. [Release 0.9.0. 2024](https://github.com/cue-lang/cue/releases/tag/v0.9.0)
38. [Release 0.9.1. 2024](https://github.com/cue-lang/cue/releases/tag/v0.9.1)
39. [Release 0.9.2. 2024](https://github.com/cue-lang/cue/releases/tag/v0.9.2)
40. [Release 0.10.0. 2024](https://github.com/cue-lang/cue/releases/tag/v0.10.0)
41. [Release 0.10.1. 2024](https://github.com/cue-lang/cue/releases/tag/v0.10.1)
42. [Release 0.11.0. 2024](https://github.com/cue-lang/cue/releases/tag/v0.11.0)
43. [Release 0.11.1. 2024](https://github.com/cue-lang/cue/releases/tag/v0.11.1)
44. [Release 0.11.2. 2025](https://github.com/cue-lang/cue/releases/tag/v0.11.2)
45. [Release 0.12.0. 2025](https://github.com/cue-lang/cue/releases/tag/v0.12.0)
46. [Release 0.12.1. 2025](https://github.com/cue-lang/cue/releases/tag/v0.12.1)
47. [Release 0.13.0. 2025](https://github.com/cue-lang/cue/releases/tag/v0.13.0)
48. [Release 0.13.1. 2025](https://github.com/cue-lang/cue/releases/tag/v0.13.1)
49. [Release 0.13.2. 2025](https://github.com/cue-lang/cue/releases/tag/v0.13.2)
50. [Release 0.14.0. 2025](https://github.com/cue-lang/cue/releases/tag/v0.14.0)